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Influence of Ni doping on the electrical and structural properties of FeSb 2
Author(s) -
Janaki J.,
Mani Awadhesh,
Satya A. T.,
Kumary T. Geetha,
Kalavathi S.,
Bharathi A.
Publication year - 2012
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201248049
Subject(s) - skutterudite , condensed matter physics , magnetoresistance , electrical resistivity and conductivity , materials science , doping , variable range hopping , atmospheric temperature range , metal–insulator transition , phase (matter) , metal , thermal conduction , chemistry , physics , thermoelectric materials , thermodynamics , magnetic field , metallurgy , organic chemistry , quantum mechanics , composite material
The influence of increasing Ni doping on the structural and magneto‐transport properties of FeSb 2 have been investigated by synthesizing Fe 1− x Ni x Sb 2 samples with x = 0–0.4 using solid‐state reaction method. The samples are single phase from x = 0–0.1 with the marcasite (FeS 2 )‐type structure. Beyond x > 0.2 the skutterudite (CoAs 3 )‐type phase starts progressively separating out apart from the required marcasite phase. The temperature‐dependent electrical resistivity studies in the range 4.2–300 K reveal activation behavior in the high‐temperature (HT) regime ( T > 70 K) with a narrow gap. The gap value increases with Ni content x . In contrast, a variable‐range hopping (VRH) type transport is seen in the low‐temperature (LT) regime. The VRH parameter T 0 progressively diminishes with increasing x . A detailed analysis of magnetoresistance using the Shklovskii–Efros model in the VRH regime indicates the increase of localization length with increasing Ni content. An insulator to metal transition is observed in the LT regime for x = 0.1. This is ascribed to arise on account of delocalization of localized states within the gap.