The low-temperature transport properties of Heusler alloy Mn₂CoAl

Epitaxial Mn₂CoAl films were grown on MgO(001) substrates by molecular beam epitaxy to study the low-temperature transport properties of a spin gapless semiconductor in view of potential applications in spintronic devices based on this unique class of materials. We present the high-quality epitaxial growth, structure characterization, temperature-dependent resistivity, and magnetoresistance results of the Mn₂CoAl films. Derived from these electronic transport properties, we found that the nearly magnetic-field-independent T 1 / 2 term originating from the electron-electron interaction effect was attributed to the resistivity behavior of the Mn₂CoAl films at low temperatures. The T 1 / 2-term interaction strength reveals a strong dependence on the structural disorder of the sample, which is in agreement with the disorder-enhanced three-dimensional electron-electron interaction effect.