Unusual transport and large diamagnetism in the intermetallic semiconductor RuAl 2
Unusual transport and large diamagnetism in the intermetallic semiconductor RuAl 2
复制标题
金属间半导体 RuAl 2 中的异常输运和大抗磁性
DOI：
10.1103/physrevb.58.3712
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发表时间：
1998
影响因子：
3.7
通讯作者：
J. Sarrao
中科院分区：
文献类型：
--
作者：
D. Mandrus;V. Keppens;B. Sales;J. Sarrao
We report measurements of the resistivity, thermopower, thermal conductivity, Hall coefficient, and magnetic susceptibility of ${\mathrm{RuAl}}_{2}$ over a wide temperature range. Room-temperature sound velocity measurements are also reported. We find that at low temperature ${\mathrm{RuAl}}_{2}$ behaves as a low carrier-density semimetal. As the temperature is raised, excitations across a 0.6-eV pseudogap dominate the transport, and ${\mathrm{RuAl}}_{2}$ behaves effectively as a semiconductor. The diamagnetic susceptibility of ${\mathrm{RuAl}}_{2}$ is anomalously large, and has an unusual temperature dependence that can be attributed to a Pauli term that reflects underlying structure in the density of states. We also suggest that the large diamagnetic response is a universal feature of hybridization gap semiconductors. The potential of ${\mathrm{RuAl}}_{2}$ for thermoelectric applications is evaluated. We find that even if the lattice component of the thermal conductivity could be reduced to its minimum value, the electrical properties of ${\mathrm{RuAl}}_{2}$ are not good enough to make it an attractive thermoelectic material.
We report measurements of the resistivity, thermopower, thermal conductivity, Hall coefficient, and magnetic susceptibility of ${\mathrm{RuAl}}_{2}$ over a wide temperature range. Room-temperature sound velocity measurements are also reported. We find that at low temperature ${\mathrm{RuAl}}_{2}$ behaves as a low carrier-density semimetal. As the temperature is raised, excitations across a 0.6-eV pseudogap dominate the transport, and ${\mathrm{RuAl}}_{2}$ behaves effectively as a semiconductor. The diamagnetic susceptibility of ${\mathrm{RuAl}}_{2}$ is anomalously large, and has an unusual temperature dependence that can be attributed to a Pauli term that reflects underlying structure in the density of states. We also suggest that the large diamagnetic response is a universal feature of hybridization gap semiconductors. The potential of ${\mathrm{RuAl}}_{2}$ for thermoelectric applications is evaluated. We find that even if the lattice component of the thermal conductivity could be reduced to its minimum value, the electrical properties of ${\mathrm{RuAl}}_{2}$ are not good enough to make it an attractive thermoelectic material.