Anisotropic magneto-thermal transport in Co$_2$MnGa thin films

Abstract

Ferromagnetic Co 2 MnGa has recently attracted significant attention due to effects related to nontrivial topology of its band structure, however a systematic study of canonical magneto-galvanic transport effects is missing. Focusing on high quality thin films, here we systematically measure anisotropic magnetoresistance (AMR) and its thermoelectric counterpart (AMTP). We model the AMR data by free energy minimisation within the Stoner-Wohlfarth formalism and conclude that both crystalline and non-crystalline components of this magneto-transport phenomenon are present in Co 2 MnGa. Unlike the AMR which is small in relative terms (∼ 0.1%), the AMTP is large due to a change of sign of the Seebeck coefficient as a function of temperature. This fact is discussed in the context of the Mott rule and further analysis of AMTP components is presented.