Ogunbunmi Michael O, Strydom André M
Highly Correlated Matter Research Group, Physics Department, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa.
J Phys Condens Matter. 2020 Jul 6;32(40). doi: 10.1088/1361-648X/ab9da2.
Here we report the magnetic, electronic and thermal transport properties of the heavy-fermion semimetal PrOsGewith a cage-like structure by means of magnetic susceptibility,(), isothermal magnetization,(,), electrical resistivity,(,), Hall coefficient,(), specific heat,(), thermal conductivity,() and thermoelectric power,().() and() show semimetallic features in a manner that mimics a thermal activated behaviour with an activation energy, Δ/= 6.5 K indicating the opening of a small energy gap in the material. At low temperatures, a Sommerfeld coefficient,= 128 mJ (molK) observed indicates a mass enhancement of the quasiparticles at low temperatures which bears witness to a heavy fermion state in PrOsGe. A Wilson-Sommerfeld ratio,and the dimensionless ratio,/of 1.01 and 0.62 ± 0.018 observed, respectively, are in good agreement with the Fermi liquid scenario.() and() reveal hole dominated transport (p-type material) with a relatively large room temperature value of() = 32.85 ± 0.98V K. A room temperature low value of() = 1.61 W K mleads to a thermoelectric figure of merit,= 0.03 ± 0.001 which is comparable to values achieved in several clathrates around the same temperature. Features from() and() favour the realization of a highervalue at elevated temperatures.
在此，我们通过磁化率（χ）、等温磁化强度（M，H）、电阻率（ρ，T）、霍尔系数（RH）、比热（C，T）、热导率（κ，T）和热电功率（S，T），报道了具有笼状结构的重费米子半金属PrOsGe的磁性、电子和热输运性质。ρ（T）和C（T）呈现出半金属特征，其方式类似于具有激活能Δ/= 6.5 K的热激活行为，表明材料中存在一个小的能隙。在低温下，观察到的索末菲系数γ = 128 mJ（mol K²）表明低温下准粒子质量增强，这证明了PrOsGe中存在重费米子态。观察到的威尔逊 - 索末菲比γ/γ0和无量纲比γ/γH分别为1.01和0.62 ± 0.018，与费米液体模型吻合良好。RH（T）和S（T）揭示了空穴主导的输运（p型材料），室温下RH值相对较大，为（RH） = 32.85 ± 0.98 μV K。室温下κ值较低，为（κ） = 1.61 W K⁻¹ m⁻¹，导致热电优值ZT = 0.03 ± 0.001，这与在相同温度下几种笼合物所达到的值相当。κ（T）和S（T）的特征有利于在高温下实现更高的ZT值。
