Pivotal role of carrier scattering for semiconductorlike transport in Fe2VAl

Abstract

A quarter century ago, a semiconductorlike resistivity was observed in the ternary Fe2VAl Heusler alloy, sparking great interest in this material. Here, we reinvestigate the origin of this temperature-dependent behavior by simultaneously analyzing experimental resistivity and Seebeck and Hall effect data in the framework of a two-band model with different energy-dependent electron relaxation times. We reveal the pivotal role of an anomalous carrier scattering mechanism off localized antisite defect states in a nominally stoichiometric and seemingly well-ordered sample, which is crucial for comprehending the semiconductorlike transport. Our work demonstrates the benefit of concurrently probing complementary transport properties such as Seebeck coefficient, Hall mobility, and electrical resistivity for understanding electronic transport phenomena in complex materials.