Ghimire N J, Botana A S, Phelan D, Zheng H, Mitchell J F
Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.
J Phys Condens Matter. 2016 Jun 15;28(23):235601. doi: 10.1088/0953-8984/28/23/235601. Epub 2016 May 10.
We report magnetic field dependent transport measurements on a single crystal of cubic YSb together with first principles calculations of its electronic structure. The transverse magnetoresistance does not saturate up to 9 T and attains a value of 75 000% at 1.8 K. The Hall coefficient is electron-like at high temperature, changes sign to hole-like between 110 and 50 K, and again becomes electron-like below 50 K. First principles calculations show that YSb is a compensated semimetal with a qualitatively similar electronic structure to that of isostructural LaSb and LaBi, but with larger Fermi surface volume. The measured electron carrier density and Hall mobility calculated at 1.8 K, based on a single band approximation, are [Formula: see text] cm(-3) and [Formula: see text] cm(2) Vs(-1), respectively. These values are comparable with those reported for LaBi and LaSb. Like LaBi and LaSb, YSb undergoes a magnetic field-induced metal-insulator-like transition below a characteristic temperature T m, with resistivity saturation below 13 K. Thickness dependent electrical resistance measurements show a deviation of the resistance behavior from that expected for a normal metal; however, they do not unambiguously establish surface conduction as the mechanism for the resistivity plateau.
我们报告了对立方 YSb 单晶进行的磁场依赖输运测量以及其电子结构的第一性原理计算。横向磁阻在高达 9 T 时不饱和,在 1.8 K 时达到 75000%的值。霍尔系数在高温下呈电子型,在 110 至 50 K 之间变为空穴型,在 50 K 以下又变为电子型。第一性原理计算表明,YSb 是一种补偿半金属,其电子结构在定性上与同结构的 LaSb 和 LaBi 相似,但费米面体积更大。基于单带近似,在 1.8 K 时测得的电子载流子密度和霍尔迁移率分别为[公式:见原文]cm⁻³和[公式:见原文]cm² V⁻¹ s⁻¹。这些值与报道的 LaBi 和 LaSb 的值相当。与 LaBi 和 LaSb 一样,YSb 在特征温度 Tm 以下经历磁场诱导的类似金属 - 绝缘体的转变,在 13 K 以下电阻率饱和。厚度依赖电阻测量表明电阻行为偏离正常金属预期;然而,它们并未明确确定表面传导是电阻率平台的机制。