Antiferromagnetic CuMnAs: Ab initio description of finite temperature magnetism and resistivity

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:513

Article

Wagenknecht, David^1,2  Vyborny, Karel³  Carva, Karel¹  Turek, Ilja² 

[1] Charles Univ Prague, Dept Condensed Matter Phys, Ke Karlovu 5, CZ-12116 Prague, Czech Republic

[2] Czech Acad Sci, Inst Phys Mat, Zizkova 22, CZ-61662 Brno, Czech Republic

[3] Czech Acad Sci, Inst Phys, Cukrovarnicka 10, CZ-16200 Prague, Czech Republic

关键词: CuMnAs;    Antiferromagnet;    Ab initio;    temperature;    Magnons;    Electrical transport;   

DOI  :  10.1016/j.jmmm.2020.167078

来源: Elsevier

【 摘 要 】

Noncollinear magnetic moments in antiferromagnets (AFM) lead to a complex behavior of electrical transport, even to a decreasing resistivity due to an increasing temperature. Proper treatment of such phenomena is required for understanding AFM systems at finite temperatures; however first-principles description of these effects is complicated. With ab initio techniques, we investigate three models of spin fluctuations (magnons) influencing the transport in AFM CuMnAs; the models are numerically feasible and easily implementable to other studies. We numerically justified a fully relativistic collinear disordered local moment approach and we present its uncompensated generalization. A saturation or a decrease of resistivity caused by magnons, phonons, and their combination (above approx. 400 K) was observed and explained by changes in electronic structure. Within the coherent potential approximation, our finite-temperature approaches may be applied also to systems with impurities, which are found to have a large impact not only on residual resistivity, but also on canting of magnetic moments from the AFM to the ferromagnetic (FM) state.

【 授权许可】

Free