Synthesis and characterization of two metallic spin-glass phases of FeMo(4)Ge(3)

Polycrystalline samples of Fe Mo4 Ge3 have been synthesized by the reduction of an oxide mixture at 1248 K and characterized by a combination of diffraction, muon spin relaxation (μ+ SR), Mössbauer spectroscopy, magnetometry, transport, and heat-capacity measurements. The compound adopts a tetragona...

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Main Authors: Baker, P, Battle, P, Blundell, S, Grandjean, F, Lancaster, T, Long, G, Oldham, SE, Prior, T
Format: Journal article
Language:English
Published: 2008
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author Baker, P
Battle, P
Blundell, S
Grandjean, F
Lancaster, T
Long, G
Oldham, SE
Prior, T
author_facet Baker, P
Battle, P
Blundell, S
Grandjean, F
Lancaster, T
Long, G
Oldham, SE
Prior, T
author_sort Baker, P
collection OXFORD
description Polycrystalline samples of Fe Mo4 Ge3 have been synthesized by the reduction of an oxide mixture at 1248 K and characterized by a combination of diffraction, muon spin relaxation (μ+ SR), Mössbauer spectroscopy, magnetometry, transport, and heat-capacity measurements. The compound adopts a tetragonal W5 Si3 structure (space group I4 mcm); the iron and molybdenum atoms are disordered over two crystallographic sites, 16k and either 4a or 4b. The synthesis conditions determine which fourfold site is selected; occupation of either leads to the presence of one-dimensional chains of transition metals in the structure. In both cases, the electrical resistivity below 200 K is ∼175 μΩ cm. The dc magnetization rapidly rises below 35 K (Fe Mo on 16k and 4b sites) or 16 K (16k and 4a sites), and a magnetization of 1 μB or 0.8 μB per Fe atom is observed in 4 T at 2 K. The ac susceptibility and the heat capacity both suggest that these are glasslike magnetic transitions, although the transition shows a more complex temperature dependence (with two maxima in χ″) when the 4b sites are partially occupied by iron. No long-range magnetic order is thought to be present at 5 K in either structural form; this has been proven by neutron diffraction and μ+ SR for the case when Fe and Mo occupy the 16k and 4b sites. © 2008 The American Physical Society.
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spelling oxford-uuid:cf74aa75-9656-451b-8521-0133e2e5a04f2022-03-27T07:42:40ZSynthesis and characterization of two metallic spin-glass phases of FeMo(4)Ge(3)Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:cf74aa75-9656-451b-8521-0133e2e5a04fEnglishSymplectic Elements at Oxford2008Baker, PBattle, PBlundell, SGrandjean, FLancaster, TLong, GOldham, SEPrior, TPolycrystalline samples of Fe Mo4 Ge3 have been synthesized by the reduction of an oxide mixture at 1248 K and characterized by a combination of diffraction, muon spin relaxation (μ+ SR), Mössbauer spectroscopy, magnetometry, transport, and heat-capacity measurements. The compound adopts a tetragonal W5 Si3 structure (space group I4 mcm); the iron and molybdenum atoms are disordered over two crystallographic sites, 16k and either 4a or 4b. The synthesis conditions determine which fourfold site is selected; occupation of either leads to the presence of one-dimensional chains of transition metals in the structure. In both cases, the electrical resistivity below 200 K is ∼175 μΩ cm. The dc magnetization rapidly rises below 35 K (Fe Mo on 16k and 4b sites) or 16 K (16k and 4a sites), and a magnetization of 1 μB or 0.8 μB per Fe atom is observed in 4 T at 2 K. The ac susceptibility and the heat capacity both suggest that these are glasslike magnetic transitions, although the transition shows a more complex temperature dependence (with two maxima in χ″) when the 4b sites are partially occupied by iron. No long-range magnetic order is thought to be present at 5 K in either structural form; this has been proven by neutron diffraction and μ+ SR for the case when Fe and Mo occupy the 16k and 4b sites. © 2008 The American Physical Society.
spellingShingle Baker, P
Battle, P
Blundell, S
Grandjean, F
Lancaster, T
Long, G
Oldham, SE
Prior, T
Synthesis and characterization of two metallic spin-glass phases of FeMo(4)Ge(3)
title Synthesis and characterization of two metallic spin-glass phases of FeMo(4)Ge(3)
title_full Synthesis and characterization of two metallic spin-glass phases of FeMo(4)Ge(3)
title_fullStr Synthesis and characterization of two metallic spin-glass phases of FeMo(4)Ge(3)
title_full_unstemmed Synthesis and characterization of two metallic spin-glass phases of FeMo(4)Ge(3)
title_short Synthesis and characterization of two metallic spin-glass phases of FeMo(4)Ge(3)
title_sort synthesis and characterization of two metallic spin glass phases of femo 4 ge 3
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