Abstract
Eu-based compounds often exhibit unusual magnetism, which is critical for nontrivial topological properties seen in materials such as EuCd2As2. The authors investigate the structure and physical properties of EuZn2As2 through measurements of the electrical resistivity, Hall effect, magnetization, and neutron diffraction. Their data show that EuZn2As2 orders antiferromagnetically with an A-type spin configuration below TN = 19 K. Surprisingly, there is strong evidence for dominant ferromagnetic fluctuations above TN, as reflected by positive Curie–Weiss temperature and extremely large negative magnetoresistance (MR) between TN and Tfl ≈200 K. Furthermore, the angle dependence of the MRab indicates field-induced spin reorientation from the ab-plane to a direction ≈45° from the ab plane. Compared to EuCd2As2, the doubled TN and Tfl make EuZn2As2 a better platform for exploring nontrivial magnetic and electronic properties in both magnetic fluctuation (TN < T < Tfl) and ordered (T < TN) regimes.
