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Anisimov MA, Samarin NA, Zhurkin VS, Bogach AV, Demishev SV, Voronov VV, Shitsevalova NY, Levchenko AV, Filipov VB, Glushkov VV. Evolution of thermoelectric properties in Eu xYb 1-xB 6family. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:465601. [PMID: 32698166 DOI: 10.1088/1361-648x/aba864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Seebeck effect in the crystalline samples of EuxYb1-xB6(x= 0, 0.082, 0.127, 0.9, 1) was investigated at temperatures 2-300 K. For all the compounds thermopower is shown to be well described by the sum of diffusion (Sd=AT) and phonon drag components. The latter contribution is induced by quasilocal (Einstein) modes of ytterbium and europium ions with characteristic temperatures ΘE(YbB6) ≈ 91 K and ΘE(EuB6) ≈ 122 K. The estimation of effective massm*of the charge carriers proves that increasing of Eu content induces crossover from 'heavy' holes withmh*(x⩽ 0.127) ≈ 0.3-0.36m0to 'light' electrons withme*(x⩾ 0.9) ≈ 0.12-0.13m0(m0-free electron mass). For the Eu-rich compounds we propose the existence of additional point on the phase diagram, which corresponds to short-range magnetic order with enhanced spin fluctuations preceding the stabilization of magnetic polarons.
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Affiliation(s)
- M A Anisimov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow 119991, Russia
| | - N A Samarin
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow 119991, Russia
| | - V S Zhurkin
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia
| | - A V Bogach
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow 119991, Russia
- National University of Science and Technology "MISIS", Moscow 119049, Russia
| | - S V Demishev
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow 119991, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia
| | - V V Voronov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow 119991, Russia
| | - N Yu Shitsevalova
- Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, Kiev 03680, Ukraine
| | - A V Levchenko
- Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, Kiev 03680, Ukraine
| | - V B Filipov
- Frantsevich Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, Kiev 03680, Ukraine
| | - V V Glushkov
- Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow 119991, Russia
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Ma X, Lu J, Whalen JB, Latturner SE. Flux Growth and Magnetoresistance Behavior of Rare Earth Zintl Phase EuMgSn. Inorg Chem 2013; 52:3342-8. [DOI: 10.1021/ic302828p] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaowei Ma
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee,
Florida 32306, United States
| | - Jun Lu
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306,
United States
| | - Jeffrey B. Whalen
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306,
United States
| | - Susan E. Latturner
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee,
Florida 32306, United States
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Kanakala R, Escudero R, Rojas-George G, Ramisetty M, Graeve OA. Mechanisms of combustion synthesis and magnetic response of high-surface-area hexaboride compounds. ACS APPLIED MATERIALS & INTERFACES 2011; 3:1093-1100. [PMID: 21438628 DOI: 10.1021/am1012276] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present an analysis of the combustion synthesis mechanisms for the preparation of hexaboride materials using three compounds as model systems: EuB(6), YbB(6), and YB(6). These three hexaborides were chosen because of the differences in ionic radii between Eu(3+), Yb(3+), and Y(3+), which is a factor in their stability. The powders were prepared using metal nitrates, carbohydrazide, and two different boron precursor powders. The resulting materials were analyzed by X-ray diffraction, which showed that combustion synthesis is effective for the synthesis of EuB(6), since the Eu(3+) ion has an ionic radius greater than ∼1 Å. The synthesis of YbB(6) and YB(6) is not as effective because of the small size of the Yb(3+) and Y(3+) ions, making the hexaborides of these metals less stable and resulting in the synthesis of borates due to the presence of oxygen during the combustion process. Scanning electron microscopy and dynamic light scattering of the EuB(6) powders shows that the particle size of the hexaboride product is dependent on the particle size of the boron precursor. The magnetic susceptibility of our EuB(6) powders manifests irreversible behavior at low applied fields, which disappears at higher fields. This behavior can be attributed to the increase in size and number of magnetic polarons with increasing magnetic field.
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Affiliation(s)
- Raghunath Kanakala
- Kazuo Inamori School of Engineering, Alfred University, 2 Pine Street, Alfred, New York 14802, USA
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Martinho H, Rettori C, Dalpian GM, da Silva JLF, Fisk Z, Oseroff SB. Evidence for a subtle structural symmetry breaking in EuB(6). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:456007. [PMID: 21694027 DOI: 10.1088/0953-8984/21/45/456007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This work presents a systematic Raman scattering study and first-principles calculations for the EuB(6) system. Evidence for the presence of an incipient (∼1 × 10(-4) Å) tetragonal symmetry break of its crystalline structure was found. Forbidden Raman modes at ω(fRm(1))∼1170 cm(-1), ω(fRm(2))∼1400 cm(-1), and ω(fRm(3))∼1500 cm(-1) were observed. The tetragonal symmetry of ω(fRm(2)) and ω(fRm(3)) together with spin-polarized first-principles simulations of the structural and magnetic properties fully support such a break of symmetry. Our data and calculations explain the occurrence of ferromagnetism in Eu hexaborides, previously reported.
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Affiliation(s)
- H Martinho
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adélia 166, 09210-170, Santo André, São Paulo, Brazil
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Goforth AM, Klavins P, Fettinger JC, Kauzlarich SM. Magnetic Properties and Negative Colossal Magnetoresistance of the Rare Earth Zintl phase EuIn2As2. Inorg Chem 2008; 47:11048-56. [DOI: 10.1021/ic801290u] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Andrea M. Goforth
- Department of Chemistry and Department of Physics, University of California, One Shields Avenue, Davis, California 95616
| | - Peter Klavins
- Department of Chemistry and Department of Physics, University of California, One Shields Avenue, Davis, California 95616
| | - James C. Fettinger
- Department of Chemistry and Department of Physics, University of California, One Shields Avenue, Davis, California 95616
| | - Susan M. Kauzlarich
- Department of Chemistry and Department of Physics, University of California, One Shields Avenue, Davis, California 95616
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Caimi G, Perucchi A, Degiorgi L, Ott HR, Pereira VM, Neto AHC, Bianchi AD, Fisk Z. Magneto-optical evidence of double exchange in a percolating lattice. PHYSICAL REVIEW LETTERS 2006; 96:016403. [PMID: 16486488 DOI: 10.1103/physrevlett.96.016403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Indexed: 05/06/2023]
Abstract
Substituting Eu by Ca in ferromagnetic EuB6 leads to a percolation limited magnetic ordering. We present and discuss magneto-optical data of the Eu(1-x)Ca(x)B6 series, based on measurements of the reflectivity R(omega) from the far infrared up to the ultraviolet, as a function of temperature and magnetic field. Via the Kramers-Kronig transformation of R(omega) we extract the complete absorption spectra of samples with different values of x. The change of the spectral weight in the Drude component by increasing the magnetic field agrees with a scenario based on the double-exchange model, and suggests a crossover from a ferromagnetic metal to a ferromagnetic Anderson insulator upon increasing Ca content at low temperatures.
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Affiliation(s)
- G Caimi
- Laboratorium für Festkörperphysik, ETH Zürich, CH-8093 Zürich, Switzerland
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Bat'ková M, Bat'ko I, Mihalik M, Konovalova ES, Shitsevalova N, Paderno Y. Electrical properties of carbon doped EuB6. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/pssc.200562485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Glazkov VN, Smirnov AI, von Nidda HAK, Loidl A, Uchinokura K, Masuda T. Field-controlled phase separation at the impurity-induced magnetic ordering in the spin-Peierls Magnet CuGeO3. PHYSICAL REVIEW LETTERS 2005; 94:057205. [PMID: 15783690 DOI: 10.1103/physrevlett.94.057205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Indexed: 05/24/2023]
Abstract
The paramagnetic fraction surviving at the impurity-induced antiferromagnetic phase transition in the spin-Peierls magnet CuGeO3 is found to increase with an external magnetic field. This effect is explained by the competition of the Zeeman interaction and of the exchange interaction of local antiferromagnetic clusters formed on the spin-gap background near impurities.
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Affiliation(s)
- V N Glazkov
- P. L. Kapitza Institute for Physical Problems RAS, 117334 Moscow, Russia.
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