1
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Syed GS, Le Gallo M, Sebastian A. Phase-Change Memory for In-Memory Computing. Chem Rev 2025. [PMID: 40403708 DOI: 10.1021/acs.chemrev.4c00670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2025]
Abstract
In-memory computing (IMC) is an emerging computational approach that addresses the processor-memory divide in modern computing systems. The core concept is to leverage the physics of memory devices and their array-level organization to perform computations directly within the memory array. Phase-change memory (PCM) is a leading memory technology being explored for IMC. In this perspective, we review the current state of phase-change materials, PCM device physics, and the design and fabrication of PCM-based IMC chips. We also provide an overview of the application landscape and offer insights into future developments.
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Affiliation(s)
| | - Manuel Le Gallo
- IBM Research-Europe, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
| | - Abu Sebastian
- IBM Research-Europe, Säumerstrasse 4, 8803 Rüschlikon, Switzerland
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2
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Moesgaard J, Fujita T, Wei S. Unveiling the boson peaks in amorphous phase-change materials. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 37:025101. [PMID: 39332450 DOI: 10.1088/1361-648x/ad80ef] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 09/27/2024] [Indexed: 09/29/2024]
Abstract
The boson peak is a universal phenomenon in amorphous solids. It can be observed as an anomalous contribution to the low-temperature heat capacity over the Debye model. Amorphous phase-change materials (PCMs) such as Ge-Sb-Te are a family of poor glass formers with fast crystallization kinetics, being of interest for phase-change memory applications. So far, whether boson peaks exist in PCMs is unknown and, if they do, their relevance to PCM properties is unclear. Here, we investigate the thermodynamic properties of the pseudo-binary compositions on the tie-line between Ge15Te85and Ge15Sb85from a few Kelvins to the liquidus temperatures. Our results demonstrate the evidence of the pronounced boson peaks in heat capacity below 10 K in the amorphous phase of all compositions. By fitting the data using the Debye model combined with a modification of the Einstein model, we can extract the characteristic parameters of the boson peaks and attribute their origin to the excess vibrational modes of dynamic defects in the amorphous solids. We find that these parameters correlate almost linearly with the Sb-content of the alloys, despite the nonmonotonic behaviors in glass forming abilities and thermal stabilities. In a broader context, we show that the correlations of the characteristic parameters of the boson peaks withTgand kinetic fragility, vary according to the type of bonding. Specifically, metallic glasses and conventional covalent glasses exhibit distinct patterns of dependence, whereas PCMs manifest characteristics that lie in between. A deeper understanding of the boson peaks in PCMs holds the promise to enable predictions of material properties at higher temperatures based on features observed in low-temperature heat capacity.
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Affiliation(s)
- Jens Moesgaard
- Department of Chemistry, Aarhus University, 8000 Aarhus, Denmark
| | - Tomoki Fujita
- Department of Chemistry, Aarhus University, 8000 Aarhus, Denmark
| | - Shuai Wei
- Department of Chemistry, Aarhus University, 8000 Aarhus, Denmark
- iMAT Centre for Integrated Materials Research, Aarhus University, 8000 Aarhus, Denmark
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3
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Qiao C, Chen L, Gu R, Liu B, Wang S, Wang S, Wang CZ, Ho KM, Xu M, Miao X. Structure, bonding and electronic characteristics of amorphous Se. Phys Chem Chem Phys 2024; 26:9510-9516. [PMID: 38450725 DOI: 10.1039/d4cp00078a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Ovonic threshold switching (OTS) selectors can effectively improve the storage density and suppress the leakage current of advanced phase-change memory devices. As a prototypical OTS material, amorphous GeSe is widely investigated. But the attention paid to amorphous Se (i.e., the functional constituent in amorphous GeSe) has been very limited up to now. Here we have explored the structure, bonding and electronic characteristics of amorphous Se using ab initio molecular dynamics simulations. The results reveal that the Se atoms in amorphous Se tend to form 2-coordinated configurations, and they connect with each other to form long chains. The fraction of the vibrational density of state located in the high frequency range is relatively large, and the formation energy of the Se-Se bond is as large as 4.44 eV, hinting that the Se-Se bonds in chains possess high stability. In addition, the mid-gap state related to the OTS behavior is also found in amorphous Se despite the small proportion. Our findings enrich the knowledge of amorphous Se, which aids the applications of Se-based OTS selectors.
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Affiliation(s)
- Chong Qiao
- School of Mathematics and Physics, Nanyang Institute of Technology, Nanyang 473004, China
| | - Lanli Chen
- School of Mathematics and Physics, Nanyang Institute of Technology, Nanyang 473004, China
| | - Rongchuan Gu
- School of Integrated Circuits, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Bin Liu
- School of Mathematics and Physics, Nanyang Institute of Technology, Nanyang 473004, China
| | - Shengzhao Wang
- School of Mathematics and Physics, Nanyang Institute of Technology, Nanyang 473004, China
| | - Songyou Wang
- Shanghai Ultra-Precision Optical Manufacturing Engineering Center and Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China
| | - Cai-Zhuang Wang
- Ames Laboratory, U. S. Department of Energy and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Kai-Ming Ho
- Ames Laboratory, U. S. Department of Energy and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - Ming Xu
- School of Integrated Circuits, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Xiangshui Miao
- School of Integrated Circuits, Huazhong University of Science and Technology, Wuhan 430074, China.
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4
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Wintersteller S, Yarema O, Kumaar D, Schenk FM, Safonova OV, Abdala PM, Wood V, Yarema M. Unravelling the amorphous structure and crystallization mechanism of GeTe phase change memory materials. Nat Commun 2024; 15:1011. [PMID: 38307863 PMCID: PMC10837456 DOI: 10.1038/s41467-024-45327-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 01/17/2024] [Indexed: 02/04/2024] Open
Abstract
The reversible phase transitions in phase-change memory devices can switch on the order of nanoseconds, suggesting a close structural resemblance between the amorphous and crystalline phases. Despite this, the link between crystalline and amorphous tellurides is not fully understood nor quantified. Here we use in-situ high-temperature x-ray absorption spectroscopy (XAS) and theoretical calculations to quantify the amorphous structure of bulk and nanoscale GeTe. Based on XAS experiments, we develop a theoretical model of the amorphous GeTe structure, consisting of a disordered fcc-type Te sublattice and randomly arranged chains of Ge atoms in a tetrahedral coordination. Strikingly, our intuitive and scalable model provides an accurate description of the structural dynamics in phase-change memory materials, observed experimentally. Specifically, we present a detailed crystallization mechanism through the formation of an intermediate, partially stable 'ideal glass' state and demonstrate differences between bulk and nanoscale GeTe leading to size-dependent crystallization temperature.
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Affiliation(s)
- Simon Wintersteller
- Chemistry and Materials Design, Institute for Electronics, Department of Information Technology and Electrical Engineering, ETH Zürich, 8092, Zürich, Switzerland
| | - Olesya Yarema
- Materials and Device Engineering, Institute for Electronics, Department of Information Technology and Electrical Engineering, ETH Zürich, 8092, Zürich, Switzerland
| | - Dhananjeya Kumaar
- Chemistry and Materials Design, Institute for Electronics, Department of Information Technology and Electrical Engineering, ETH Zürich, 8092, Zürich, Switzerland
| | - Florian M Schenk
- Chemistry and Materials Design, Institute for Electronics, Department of Information Technology and Electrical Engineering, ETH Zürich, 8092, Zürich, Switzerland
| | | | - Paula M Abdala
- Laboratory of Energy Science and Engineering, Department of Mechanical and Process Engineering, ETH Zurich, 8092, Zürich, Switzerland
| | - Vanessa Wood
- Materials and Device Engineering, Institute for Electronics, Department of Information Technology and Electrical Engineering, ETH Zürich, 8092, Zürich, Switzerland
| | - Maksym Yarema
- Chemistry and Materials Design, Institute for Electronics, Department of Information Technology and Electrical Engineering, ETH Zürich, 8092, Zürich, Switzerland.
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5
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Fujita T, Chen Y, Kono Y, Takahashi S, Kasai H, Campi D, Bernasconi M, Ohara K, Yumoto H, Koyama T, Yamazaki H, Senba Y, Ohashi H, Inoue I, Hayashi Y, Yabashi M, Nishibori E, Mazzarello R, Wei S. Pressure-induced reversal of Peierls-like distortions elicits the polyamorphic transition in GeTe and GeSe. Nat Commun 2023; 14:7851. [PMID: 38062025 PMCID: PMC10703813 DOI: 10.1038/s41467-023-43457-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 11/09/2023] [Indexed: 03/06/2025] Open
Abstract
While polymorphism is prevalent in crystalline solids, polyamorphism draws increasing interest in various types of amorphous solids. Recent studies suggested that supercooling of liquid phase-change materials (PCMs) induces Peierls-like distortions in their local structures, underlying their liquid-liquid transitions before vitrification. However, the mechanism of how the vitrified phases undergo a possible polyamorphic transition remains elusive. Here, using high-energy synchrotron X-rays, we can access the precise pair distribution functions under high pressure and provide clear evidence that pressure can reverse the Peierls-like distortions, eliciting a polyamorphic transition in GeTe and GeSe. Combined with simulations based on machine-learned-neural-network potential, our structural analysis reveals a high-pressure state characterized by diminished Peierls-like distortion, greater coherence length, reduced compressibility, and a narrowing bandgap. Our finding underscores the crucial role of Peierls-like distortions in amorphous octahedral systems including PCMs. These distortions can be controlled through pressure and composition, offering potentials for designing properties in PCM-based devices.
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Affiliation(s)
- Tomoki Fujita
- Department of Chemistry, Aarhus University, 8000, Aarhus C, Denmark
| | - Yuhan Chen
- Department of Physics, Sapienza University of Rome, Rome, 00185, Italy
| | - Yoshio Kono
- Geodynamics Research Center, Ehime University, Matsuyama, 790-8577, Japan
| | - Seiya Takahashi
- Department of Physics, Faculty of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, Ibaraki, 305-8571, Japan
| | - Hidetaka Kasai
- Department of Physics, Faculty of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, Ibaraki, 305-8571, Japan
| | - Davide Campi
- Department of Materials Science, University of Milano-Bicocca, I-20125, Milano, Italy
| | - Marco Bernasconi
- Department of Materials Science, University of Milano-Bicocca, I-20125, Milano, Italy
| | - Koji Ohara
- Faculty of Materials for Energy, Shimane University, Matsue, Shimane, 690-8504, Japan
| | - Hirokatsu Yumoto
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Takahisa Koyama
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Hiroshi Yamazaki
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Yasunori Senba
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Haruhiko Ohashi
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Ichiro Inoue
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Yujiro Hayashi
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Makina Yabashi
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5148, Japan
| | - Eiji Nishibori
- Department of Physics, Faculty of Pure and Applied Sciences and Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, Ibaraki, 305-8571, Japan
| | | | - Shuai Wei
- Department of Chemistry, Aarhus University, 8000, Aarhus C, Denmark.
- iMAT Centre for Integrated Materials Research, Aarhus University, Aarhus, Denmark.
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6
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Shen X, Zhou Y, Zhang H, Deringer VL, Mazzarello R, Zhang W. Surface effects on the crystallization kinetics of amorphous antimony. NANOSCALE 2023; 15:15259-15267. [PMID: 37674458 DOI: 10.1039/d3nr03536k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Elemental antimony (Sb) is regarded as a promising candidate to improve the programming consistency and cycling endurance of phase-change memory and neuro-inspired computing devices. Although bulk amorphous Sb crystallizes spontaneously, the stability of the amorphous form can be greatly increased by reducing the thickness of thin films down to several nanometers, either with or without capping layers. Computational and experimental studies have explained the depressed crystallization kinetics caused by capping and interfacial confinement; however, it is unclear why amorphous Sb thin films remain stable even in the absence of capping layers. In this work, we carry out thorough ab initio molecular dynamics (AIMD) simulations to investigate the effects of free surfaces on the crystallization kinetics of amorphous Sb. We reveal a stark contrast in the crystallization behavior between bulk and surface models at 450 K, which stems from deviations from the bulk structural features in the regions approaching the surfaces. The presence of free surfaces intrinsically tends to create a sub-nanometer region where crystallization is suppressed, which impedes the incubation process and thus constrains the nucleation in two dimensions, stabilizing the amorphous phase in thin-film Sb-based memory devices.
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Affiliation(s)
- Xueyang Shen
- Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Yuxing Zhou
- Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, Oxford, OX1 3QR, UK
| | - Hanyi Zhang
- Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Volker L Deringer
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, Oxford, OX1 3QR, UK
| | | | - Wei Zhang
- Center for Alloy Innovation and Design (CAID), State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
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7
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Di Lisio V, Gallino I, Riegler SS, Frey M, Neuber N, Kumar G, Schroers J, Busch R, Cangialosi D. Size-dependent vitrification in metallic glasses. Nat Commun 2023; 14:4698. [PMID: 37542023 PMCID: PMC10403508 DOI: 10.1038/s41467-023-40417-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 07/26/2023] [Indexed: 08/06/2023] Open
Abstract
Reducing the sample size can profoundly impact properties of bulk metallic glasses. Here, we systematically reduce the length scale of Au and Pt-based metallic glasses and study their vitrification behavior and atomic mobility. For this purpose, we exploit fast scanning calorimetry (FSC) allowing to study glassy dynamics in an exceptionally wide range of cooling rates and frequencies. We show that the main α relaxation process remains size independent and bulk-like. In contrast, we observe pronounced size dependent vitrification kinetics in micrometer-sized glasses, which is more evident for the smallest samples and at low cooling rates, resulting in more than 40 K decrease in fictive temperature, Tf, with respect to the bulk. We discuss the deep implications on how this outcome can be used to convey glasses to low energy states.
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Affiliation(s)
- Valerio Di Lisio
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018, San Sebastián, Spain
| | - Isabella Gallino
- Saarland University, Chair of Metallic Materials, Campus C6.3, 66123, Saarbrücken, Germany.
| | | | - Maximilian Frey
- Saarland University, Chair of Metallic Materials, Campus C6.3, 66123, Saarbrücken, Germany
| | - Nico Neuber
- Saarland University, Chair of Metallic Materials, Campus C6.3, 66123, Saarbrücken, Germany
| | - Golden Kumar
- Department of Mechanical Engineering, University of Texas at Dallas, Richardson, TX, USA
| | - Jan Schroers
- Yale University, Mechanical Engineering and Materials Science, New Haven, CT, USA
| | - Ralf Busch
- Saarland University, Chair of Metallic Materials, Campus C6.3, 66123, Saarbrücken, Germany
| | - Daniele Cangialosi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018, San Sebastián, Spain.
- Centro de Física de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, 20018, San Sebastián, Spain.
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8
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Wang X, Sun S, Wang J, Li S, Zhou J, Aktas O, Xu M, Deringer VL, Mazzarello R, Ma E, Zhang W. Spin Glass Behavior in Amorphous Cr 2 Ge 2 Te 6 Phase-Change Alloy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2302444. [PMID: 37279377 PMCID: PMC10427411 DOI: 10.1002/advs.202302444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Indexed: 06/08/2023]
Abstract
The layered crystal structure of Cr2 Ge2 Te6 shows ferromagnetic ordering at the two-dimensional limit, which holds promise for spintronic applications. However, external voltage pulses can trigger amorphization of the material in nanoscale electronic devices, and it is unclear whether the loss of structural ordering leads to a change in magnetic properties. Here, it is demonstrated that Cr2 Ge2 Te6 preserves the spin-polarized nature in the amorphous phase, but undergoes a magnetic transition to a spin glass state below 20 K. Quantum-mechanical computations reveal the microscopic origin of this transition in spin configuration: it is due to strong distortions of the CrTeCr bonds, connecting chromium-centered octahedra, and to the overall increase in disorder upon amorphization. The tunable magnetic properties of Cr2 Ge2 Te6 can be exploited for multifunctional, magnetic phase-change devices that switch between crystalline and amorphous states.
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Affiliation(s)
- Xiaozhe Wang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Suyang Sun
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Jiang‐Jing Wang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Shuang Li
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Jian Zhou
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Oktay Aktas
- State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Ming Xu
- Wuhan National Laboratory for OptoelectronicsSchool of Integrated CircuitsHuazhong University of Science and TechnologyWuhan430074China
| | - Volker L. Deringer
- Department of ChemistryInorganic Chemistry LaboratoryUniversity of OxfordOxfordOX1 3QRUK
| | | | - En Ma
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Wei Zhang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
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9
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Highly tunable β-relaxation enables the tailoring of crystallization in phase-change materials. Nat Commun 2022; 13:7352. [DOI: 10.1038/s41467-022-35005-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 11/15/2022] [Indexed: 11/30/2022] Open
Abstract
AbstractIn glasses, secondary (β-) relaxations are the predominant source of atomic dynamics. Recently, they have been discovered in covalently bonded glasses, i.e., amorphous phase-change materials (PCMs). However, it is unclear what the mechanism of β-relaxations is in covalent systems and how they are related to crystallization behaviors of PCMs that are crucial properties for non-volatile memories and neuromorphic applications. Here we show direct evidence that crystallization is strongly linked to β-relaxations. We find that the β-relaxation in Ge15Sb85 possesses a high tunability, which enables a manipulation of crystallization kinetics by an order of magnitude. In-situ synchrotron X-ray scattering, dielectric functions, and ab-initio calculations indicate that the weakened β-relaxation intensity stems from a local reinforcement of Peierls-like distortions, which increases the rigidity of the bonding network and decreases the dynamic heterogeneity. Our findings offer a conceptually new approach to tuning the crystallization of PCMs based on manipulating the β-relaxations.
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10
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Seo Y, Zuo B, Cangialosi D, Priestley RD. Physical aging of hydroxypropyl methylcellulose acetate succinate via enthalpy recovery. SOFT MATTER 2022; 18:8331-8341. [PMID: 36300535 DOI: 10.1039/d2sm01189a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Amorphous solid dispersions (ASDs) utilize the kinetic stability of the amorphous state to stabilize drug molecules within a glassy polymer matrix. Therefore, understanding the glassy-state stability of the polymer excipient is critical to ASD design and performance. Here, we investigated the physical aging of hydroxypropyl methylcellulose acetate succinate (HPMCAS), a commonly used polymer in ASD formulations. We found that HPMCAS exhibited conventional physical aging behavior when annealed near the glass transition temperature (Tg). In this scenario, structural recovery was facilitated by α-relaxation dynamics. However, when annealed well below Tg, a sub-α-relaxation process facilitated low-temperature physical aging in HPMCAS. Nevertheless, the physical aging rate exhibited no significant change up to 40 K below Tg, below which it exhibited a near monotonic decrease with decreasing temperature. Finally, infrared spectroscopy was employed to assess any effect of physical aging on the chemical structure of HPMCAS, which is known to be susceptible to degradation at temperatures 30 K above its Tg. Our results provide critical insights necessary to understand better the link between the stability of ASDs and physical aging of the glassy polymer matrix.
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Affiliation(s)
- Yejoon Seo
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08540, USA
| | - Biao Zuo
- Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Daniele Cangialosi
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizábal 4, 20018, San Sebastián, Spain
- Centro de Fisica de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizábal 5, 20018, San Sebastián, Spain
| | - Rodney D Priestley
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08540, USA
- Princeton Institute for the Science and Technology of Materials, Princeton University, 41 Olden St, A215 Chemical and Biological Engineering, Princeton, New Jersey 08540, USA.
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11
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Peng SX, Yin Z, Zhang T, Yang Q, Yu H, ZENG M. Vibration assisted glass-formation in zeolitic imidazolate framework. J Chem Phys 2022; 157:104501. [DOI: 10.1063/5.0109885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
New glass forming method is essential for broadening the scope of liquid and glassy metal-organic frameworks (MOFs) due to limitations of the conventional melt-quenching method. Herein we show that in-situ mechanical vibration can facilitate the framework melting at lower temperature and produce glassy MOFs with unique properties. Using ZIF-62 as a concept-proofing material, in-situ mechanical vibration enables low-temperature melting at 653 K, far below its melting point (713 K). The resulted vibrated ZIF-62 glass exhibited a lower glass transition temperature of 545 K, improved gas accessible porosity and pronounced short-to-medium range structures compared to the corresponding melt-quenched glass. We propose that vibration facilitated surface reconstruction facilitates pre-melting, which could be the cause of the lowered melting temperature. The vibration assisted method represents a new general method to produce MOF glasses without thermal decomposition.
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Affiliation(s)
| | - Zheng Yin
- Shaanxi University of Science and Technology, China
| | - Tao Zhang
- Huazhong University of Science and Technology, China
| | - Qun Yang
- Huazhong University of Science and Technology, China
| | - HaiBin Yu
- Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, China
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12
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Dragoni D, Behler J, Bernasconi M. Mechanism of amorphous phase stabilization in ultrathin films of monoatomic phase change material. NANOSCALE 2021; 13:16146-16155. [PMID: 34542138 DOI: 10.1039/d1nr03432d] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Elemental antimony has been recently proposed as a promising material for phase change memories with improved performances with respect to the most used ternary chalcogenide alloys. The compositional simplification prevents reliability problems due to demixing of the alloy during memory operation. This is made possible by the dramatic stabilization of the amorphous phase once Sb is confined in an ultrathin film 3-5 nm thick. In this work, we shed light on the microscopic origin of this effect by means of large scale molecular dynamics simulations based on an interatomic potential generated with a machine learning technique. The simulations suggest that the dramatic reduction of the crystal growth velocity in the film with respect to the bulk is due to the effect of nanoconfinement on the fast β relaxation dynamics while the slow α relaxation is essentially unaffected.
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Affiliation(s)
- Daniele Dragoni
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via R. Cozzi 55, I-20125 Milano, Italy.
| | - Jörg Behler
- Institut für Physikalische Chemie, Theoretische Chemie, Universität Göttingen, Tammannstr. 6, 37077 Göttingen, Germany
| | - Marco Bernasconi
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via R. Cozzi 55, I-20125 Milano, Italy.
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Yang Q, Pei CQ, Yu HB, Feng T. Metallic Nanoglasses with Promoted β-Relaxation and Tensile Plasticity. NANO LETTERS 2021; 21:6051-6056. [PMID: 34240612 DOI: 10.1021/acs.nanolett.1c01283] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The secondary (β) relaxation is an intrinsic feature of glassy systems and is crucial for the mechanical properties of metallic glasses. However, it remains puzzling what structural features control the β-relaxation fundamentally. Here, we use the recently developed nanoglasses exhibiting well-defined structural features at the nanometer scale to interrogate such structure-dynamics relations. We show that an electrodeposited Ni77.5P22.5 nanoglass exhibits promoted β-relaxation and enhanced microscale tensile plasticity over the most rapidly melt-quenched metallic glass with the same composition. Structurally, the β-relaxation is sensitive to the interfacial regions among grains in the nanoglasses. Our results reveal a clear correlation between the amorphous nanostructures and the β-relaxation. It seems that the nanostructuring represents a novel route to obtain high-energy glassy states, that is, the inverse problem of the ultrastable glass.
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Affiliation(s)
- Qun Yang
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, Hubei China
| | - Chao-Qun Pei
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Hai-Bin Yu
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, Hubei China
| | - Tao Feng
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
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Hultmark S, Cravcenco A, Kushwaha K, Mallick S, Erhart P, Börjesson K, Müller C. Vitrification of octonary perylene mixtures with ultralow fragility. SCIENCE ADVANCES 2021; 7:7/29/eabi4659. [PMID: 34272241 PMCID: PMC8284888 DOI: 10.1126/sciadv.abi4659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 06/02/2021] [Indexed: 05/08/2023]
Abstract
Strong glass formers with a low fragility are highly sought-after because of the technological importance of vitrification. In the case of organic molecules and polymers, the lowest fragility values have been reported for single-component materials. Here, we establish that mixing of organic molecules can result in a marked reduction in fragility. Individual bay-substituted perylene derivatives display a high fragility of more than 70. Instead, slowly cooled perylene mixtures with more than three components undergo a liquid-liquid transition and turn into a strong glass former. Octonary perylene mixtures display a fragility of 13 ± 2, which not only is a record low value for organic molecules but also lies below values reported for the strongest known inorganic glass formers. Our work opens an avenue for the design of ultrastrong organic glass formers, which can be anticipated to find use in pharmaceutical science and organic electronics.
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Affiliation(s)
- Sandra Hultmark
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Göteborg, Sweden
| | - Alex Cravcenco
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemigården 4, 41296 Göteborg, Sweden
| | - Khushbu Kushwaha
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemigården 4, 41296 Göteborg, Sweden
| | - Suman Mallick
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemigården 4, 41296 Göteborg, Sweden
| | - Paul Erhart
- Department of Physics, Chalmers University of Technology, 41296 Göteborg, Sweden
| | - Karl Börjesson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemigården 4, 41296 Göteborg, Sweden
| | - Christian Müller
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Göteborg, Sweden.
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Monnier X, Marina S, Lopez de Pariza X, Sardón H, Martin J, Cangialosi D. Physical Aging Behavior of a Glassy Polyether. Polymers (Basel) 2021; 13:954. [PMID: 33804594 PMCID: PMC8003685 DOI: 10.3390/polym13060954] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/16/2021] [Accepted: 03/17/2021] [Indexed: 11/16/2022] Open
Abstract
The present work aims to provide insights on recent findings indicating the presence of multiple equilibration mechanisms in physical aging of glasses. To this aim, we have investigated a glass forming polyether, poly(1-4 cyclohexane di-methanol) (PCDM), by following the evolution of the enthalpic state during physical aging by fast scanning calorimetry (FSC). The main results of our study indicate that physical aging persists at temperatures way below the glass transition temperature and, in a narrow temperature range, is characterized by a two steps evolution of the enthalpic state. Altogether, our results indicate that the simple old-standing view of physical aging as triggered by the α relaxation does not hold true when aging is carried out deep in the glassy state.
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Affiliation(s)
- Xavier Monnier
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain;
| | - Sara Marina
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
| | - Xabier Lopez de Pariza
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
| | - Haritz Sardón
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
| | - Jaime Martin
- POLYMAT, University of the Basque Country UPV/EHU, Av. de Tolosa 72, 20018 San Sebastián, Spain; (S.M.); (X.L.d.P.); (H.S.); (J.M.)
- Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
- Centro de Investigacións Tecnolóxicas, Universidade da Coruña, Campus de Esteiro s/n, 15403 Ferrol, Spain
| | - Daniele Cangialosi
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain;
- Centro de Fisica de Materiales (CSIC-UPV/EHU) Paseo Manuel de Lardizabal 5, 20018 Sebastián, Spain
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Rozwadowski T, Jasiurkowska-Delaporte M, Massalska-Arodź M, Yamamura Y, Saito K. Designing the disorder: the kinetics of nonisothermal crystallization of the orientationally disordered crystalline phase in a nematic mesogen. Phys Chem Chem Phys 2020; 22:24236-24248. [PMID: 33084672 DOI: 10.1039/d0cp04002a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This article presents the molecular dynamics and solidification behavior of a 2,3-difluoro-4-propylphenyl 2,3-difluoro-4-(4-pentylcyclohexyl)benzoate nematic liquid crystal (5C4FPB3) observed by broadband dielectric spectroscopy (BDS) and differential scanning calorimetry (DSC). Polarized optical microscopy (POM) is also performed to confirm the phase transition temperatures. Our investigation reveals rare crystallization of the orientationally disordered crystal (ODIC) phase from the nematic phase and a glass transition of the crystal at cooling rates higher than 1 K min-1. The deconvolution of the dielectric spectra with derivative techniques is necessary because of the complex molecular dynamics in the crystalline phase. The BDS method enables us to capture the relaxation processes reflecting pre-crystallization molecular movements. The kinetics of nonisothermal crystallization is studied using the Ozawa, Mo, and isoconversional methods. The present studies suggest that the dominant factor of the crystal growth mechanism depends on the cooling rate. Two types of crystallization mechanisms are identified at cooling rates lower and higher than 5 K min-1. We design a diagram with crystallization and glass transition borders against the cooling rates. Estimations show that crystallization of the present compound can be bypassed at cooling rates higher than 78 kK min-1, at which a glass transition of the nematic phase occurs. We show various scenarios of the molecular order and the crystallization mechanism designed based on the process rate.
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Affiliation(s)
- Tomasz Rozwadowski
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan. and Institute of Nuclear Physics Polish Academy of Sciences, PL-31342 Krakow, Poland
| | | | | | - Yasuhisa Yamamura
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
| | - Kazuya Saito
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan.
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