Unusual Electrical and Magnetic Properties in Layered EuZn <sub>2</sub> As <sub>2</sub>
Joanna Bławat, Madalynn Marshall, John Singleton, Erxi Feng, Huibo Cao, Weiwei Xie, Rongying Jin
Abstract
Abstract Eu‐based compounds often exhibit unusual magnetism, which is critical for nontrivial topological properties seen in materials such as EuCd 2 As 2 . The authors investigate the structure and physical properties of EuZn 2 As 2 through measurements of the electrical resistivity, Hall effect, magnetization, and neutron diffraction. Their data show that EuZn 2 As 2 orders antiferromagnetically with an A‐type spin configuration below T N = 19 K. Surprisingly, there is strong evidence for dominant ferromagnetic fluctuations above T N , as reflected by positive Curie–Weiss temperature and extremely large negative magnetoresistance (MR) between T N and T fl ≈200 K. Furthermore, the angle dependence of the MR ab indicates field‐induced spin reorientation from the ab ‐plane to a direction ≈45° from the ab plane. Compared to EuCd 2 As 2 , the doubled T N and T fl make EuZn 2 As 2 a better platform for exploring nontrivial magnetic and electronic properties in both magnetic fluctuation ( T N < T < T fl ) and ordered ( T < T N ) regimes.