We report a combined theoretical and experimental study of a novel quaternary Heusler system CoFeVSb from the view point of room temperature spintronics and thermoelectric applications. It crystallizes in cubic structure with small DO3-type disorder. The presence of disorder is confirmed by room temperature synchrotron X-ray diffraction(XRD) and extended X-ray absorption fine structure (EXAFS) measurements. Magnetization data reveal high ordering temperature with a saturation magnetization of 2.2 μB/f.u. Resistivity measurements reflect half-metallic nature. Double hysteresis loop along with asymmetry in the magnetoresistance(MR) data reveals room temperature spin-valve feature, which remains stable even at 300 K. Hall measurements show anomalous behavior with significant contribution from intrinsic Berry phase. This compound also large room temperature power factor (∼0.62 mWatt/m/K2) and ultra low lattice thermal conductivity (∼0.4 W/m/K), making it a promising candidate for thermoelectric application. Ab-initio calculations suggest weak half-metallic behavior and reduced magnetization (in agreement with experiment) in presence of DO3 disorder. We have also found an energetically competing ferromagnetic FM)/antiferromagnetic (AFM) interface structure within an otherwise FM matrix: one of the prerequisites for spin valve behavior. Coexistence of so many promising features in a single system is rare, and hence CoFeVSb gives a fertile platform to explore numerous applications in future.
@article{arxiv.2111.14081,
title = {CoFeVSb: A Promising Candidate for Spin Valve and Thermoelectric Applications},
author = {Jadupati Nag and Deepika Rani and Durgesh Singh and R. Venkatesh and Bhawna Sahni and A. K. Yadav and S. N. Jha and D. Bhattacharyya and P. D. Babu and K. G. Suresh and Aftab Alam},
journal= {arXiv preprint arXiv:2111.14081},
year = {2022}
}