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Song M, Xian C, Wang Y, Song J, Li Z, Ling L, Zhang L, Han Y, Cao L, Xiong Y. Disorder-driven non-Fermi liquid behavior in itinerant ferromagnet α-Co 5Ge 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:155802. [PMID: 31846939 DOI: 10.1088/1361-648x/ab62be] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The physical properties of itinerant ferromagnet [Formula: see text]-Co5Ge3 with both strong disorder and spin fluctuations was studied. The dc and ac susceptibility show that both spin fluctuations and disorder dominate the physical properties. In the spin glass phase, with a coexisting ferromagnetic state ([Formula: see text]30 K), both non-Fermi liquid behavior and large exponent of scaling relation of [Formula: see text] are observed and attributed to the spin fluctuations and disorder induced by cobalt defects. Upon the increase of external field, Fermi liquid behavior restores due to the suppression of spin fluctuations and disorder. In addition, a large anomalous Hall coefficient R s is observed. Our results suggest that [Formula: see text]-Co5Ge3 is a typical itinerant ferromagnet to explore the interplay of disorder and spin fluctuations.
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Affiliation(s)
- Meng Song
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory of the Chinese Academy of Sciences, Hefei, Anhui 230031, People's Republic of China. University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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Tosun O, Abel FM, Balasubramanian B, Skomski R, Sellmyer DJ, Hadjipanayis GC. Structure and Magnetism of Co 2Ge Nanoparticles. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 9:nano9101371. [PMID: 31557827 PMCID: PMC6836187 DOI: 10.3390/nano9101371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/22/2019] [Accepted: 09/22/2019] [Indexed: 06/10/2023]
Abstract
The structural and magnetic properties of Co2Ge nanoparticles (NPs) prepared by the cluster-beam deposition (CBD) technique have been investigated. As-made particles with an average size of 5.5 nm exhibit a mixture of hexagonal and orthorhombic crystal structures. Thermomagnetic measurements showed that the as-made particles are superparamagnetic at room temperature with a blocking temperature (TB) of 20 K. When the particles are annealed at 823 K for 12 h, their size is increased to 13 nm and they develop a new orthorhombic crystal structure, with a Curie temperature (TC) of 815 K. This is drastically different from bulk, which are ferromagnetic at cryogenic temperatures only. X-ray diffraction (XRD) measurements suggest the formation of a new Co-rich orthorhombic phase (OP) with slightly increased c/a ratio in the annealed particles and this is believed to be the reason for the drastic change in their magnetic properties.
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Affiliation(s)
- Onur Tosun
- Department of Physics and Astronomy, University of Delaware, Newark, DE 19711, USA.
| | - Frank M Abel
- Department of Physics and Astronomy, University of Delaware, Newark, DE 19711, USA.
| | - Balamurugan Balasubramanian
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE 68588, USA.
- Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588, USA.
| | - Ralph Skomski
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE 68588, USA.
- Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588, USA.
| | - David J Sellmyer
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE 68588, USA.
- Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588, USA.
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Zhou GF, Bakker H. Mechanically induced structural and magnetic changes in the GdAl2 Laves phase. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:9437-9445. [PMID: 9979990 DOI: 10.1103/physrevb.52.9437] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Zhou GF, Bakker H. Influence of Mechanical Milling on Magnetic Properties of Intermetallic Compounds ( Overview). ACTA ACUST UNITED AC 1995. [DOI: 10.2320/matertrans1989.36.329] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- G. F. Zhou
- Van der Waals-Zeeman Laboratorium, Universiteit van Amsterdam
| | - H. Bakker
- Van der Waals-Zeeman Laboratorium, Universiteit van Amsterdam
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Zhou G, Bakker H. Atomic disorder and phase transformation in L12-structure Ni3Si by ball milling. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/0956-7151(94)90397-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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