Two-step magnetic ordering into a canted state in ferrimagnetic monoclinic Mn3As2

Abstract

We report the magnetic structure of monoclinic Mn3As2 at 3 ​K and 250 ​K using neutron powder diffraction measurements. From magnetometry data, the Curie temperature of Mn3As2 was confirmed to be around 270 ​K. Calorimetry analysis showed the presence of another transition at 225 ​K. At 270 ​K, Mn3As2 undergoes a k=0 ferrimagnetic ordering in the magnetic space group C2/m (#12.58) with Mn moments pointing along b. Below 225 ​K, there is a canting of Mn moments in the ac plane which produces a multi-k non-collinear magnetic structure in space group C2/c (#15.85). The components of Mn moments along b follow k=0 ordering and the components along a and c have k=[0012] propagation vector. The change in the magnetic ground state with temperature provides a deeper insight into the factors that govern magnetic ordering in Mn–As compounds. © 2020 Elsevier Inc.