Correlation of anomalous Hall effect with structural parameters and magnetic ordering in Mn3+<i>x</i>Sn1−<i>x</i> thin films

Abstract

We investigate the relationship between structural parameters, magnetic ordering, and the anomalous Hall effect (AHE) of Mn3+xSn1−x (−0.42 ≤ x ≤ +0.23) thin films annealed at various temperatures Ta. The crystal structure changes with x and Ta, and at Ta ≥ 500 °C near the stoichiometric composition (−0.08 ≤ x ≤ +0.04), epitaxial single-phase D019-Mn3+xSn1−x(101̄0) is obtained. At room temperature, a larger AHE is obtained when the single-phase epitaxial Mn3Sn with the lattice constant closer to that of bulk is formed. The temperature dependence of the AHE shows different behaviors depending on Ta and can be explained by considering the variation of magnetic ordering. A close inspection into the temperature and composition dependence suggests a variation of magnetic phase transition temperature with composition and/or a possible correlation between the AHE and Fermi level position with respect to the Weyl points. Our comprehensive study on (101̄0)-oriented epitaxial Mn3Sn thin films would provide the basis for utilizing the unique functionalities of non-collinear antiferromagnetic materials.