Giant magnetoresistance and topological Hall effect in the EuGa4 antiferromagnet. (3rd November 2021)

• Record Type: Journal Article
• Authors: Zhang, H; Zhu, X Y; Xu, Y; Gawryluk, D J; Xie, W; Ju, S L; Shi, M; Shiroka, T; Zhan, Q F; Pomjakushina, E; Shang, T
• Is Part Of: Journal of physics. Volume 34:Number 3(2022)
• Publication Date: 2021-11-03
• Subjects: magnetoresistance -- topological Hall effect -- topological spin textures; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ac3102
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We report on systematic temperature- and magnetic field-dependent studies of the EuGa4 binary compound, which crystallizes in a centrosymmetric tetragonal BaAl4 -type structure with space group I 4/ mmm . The electronic properties of EuGa4 single crystals, with an antiferromagnetic (AFM) transition at T N ∼ 16.4 K, were characterized via electrical resistivity and magnetization measurements. A giant nonsaturating magnetoresistance was observed at low temperatures, reaching ∼ 7 × 1 0 4 % at 2 K in a magnetic field of 9 T. In the AFM state, EuGa4 undergoes a series of metamagnetic transitions in an applied magnetic field, clearly manifested in its field-dependent electrical resistivity. Below T N, in the ∼4–7 T field range, we observe also a clear hump-like anomaly in the Hall resistivity which is part of the anomalous Hall resistivity. We attribute such a hump-like feature to the topological Hall effect, usually occurring in noncentrosymmetric materials known to host topological spin textures (as e.g., magnetic skyrmions). Therefore, the family of materials with a tetragonal BaAl4 -type structure, to which EuGa4 and EuAl4 belong, seems to comprise suitable candidates on which one can study the interplay among correlated-electron phenomena (such as charge-density wave or exotic magnetism) with topological spin textures and topologically nontrivial bands.