Condensed Matter Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu, India.
J Phys Condens Matter. 2012 Feb 22;24(7):075601. doi: 10.1088/0953-8984/24/7/075601. Epub 2012 Feb 2.
The evolution of the ground state properties of FeSb(2) has been investigated via temperature (4.2-300 K), magnetic field (0-12 T) and pressure (0-8.8 GPa) dependent electrical resistivity studies. The temperature dependence of the resistivity follows activated behavior in the high temperature (HT) regime (T > 60 K), while variable range hopping (VRH) dictates the transport in the intermediate temperature (IT) regime (10 K > T > 45 K) and power law behavior is observed in the low temperature (LT) regime (T < 10 K). The pressure profoundly affects the resistivity in all the temperature regimes. The energy gap (Δ) extracted in the HT regime initially increases with pressure and then decreases, while the VRH parameter T(0) deduced in the IT regime is seen to decrease monotonically and vanish beyond 5 GPa leading to an insulator to metal transition (MIT) on account of delocalization of the electronic states in the gap. The analysis of the logarithmic derivative of the conductivity indicates the MIT to occur at ~6 GPa. The magnetoresistivity is found to be positive. The analysis of the resistivity behavior under pressure and magnetic field indicates that the former induces delocalization, while the latter tends to assist localization of the defect states inside the gap of FeSb(2).
通过温度（4.2-300 K）、磁场（0-12 T）和压力（0-8.8 GPa）相关的电阻率研究，研究了 FeSb(2) 的基态性质的演化。电阻率的温度依赖性在高温（HT）区（T > 60 K）遵循激活行为，而变程跳跃（VRH）在中间温度（IT）区（10 K > T > 45 K）决定了输运，并且在低温（LT）区（T < 10 K）观察到幂律行为。压力在所有温度区都对电阻率有很大的影响。在 HT 区提取的能隙（Δ）最初随压力增加而增加，然后减小，而在 IT 区推断出的 VRH 参数 T(0) 则单调减小，并在超过 5 GPa 时消失，导致由于电子态在能带中的离域而发生金属-绝缘体转变（MIT）。对电导率的对数导数的分析表明，MIT 发生在约 6 GPa。磁阻被发现是正的。对压力和磁场下电阻率行为的分析表明，前者诱导离域，而后者倾向于协助在 FeSb(2) 的能带中的缺陷态的局域化。
