Options
CoFeVSb: A promising candidate for spin valve and thermoelectric applications
Journal
Physical Review B
ISSN
24699950
Date Issued
2022-04-01
Author(s)
Nag, Jadupati
Rani, Deepika
Singh, Durgesh
Venkatesh, R.
Sahni, Bhawna
Yadav, A. K.
Jha, S. N.
Bhattacharyya, D.
Babu, P. D.
Suresh, K. G.
Alam, Aftab
Abstract
We report a combined theoretical and experimental study of a novel quaternary Heusler system, CoFeVSb, from the viewpoint of room-temperature spintronics and thermoelectric applications. CoFeVSb crystallizes in a cubic structure with a small DO3-type disorder. The presence of the disorder is confirmed by room-temperature synchrotron x-ray diffraction and extended x-ray absorption fine structure measurements. Magnetization data reveal a high ordering temperature (∼850K) with a saturation magnetization of 2.2 μB/f.u. Resistivity measurements indicate a half-metallic or semimetallic nature. A double hysteresis loop along with asymmetry in the magnetoresistance data reveals a room-temperature spin valve feature, which remains stable even at 300 K. Hall measurements show anomalous behavior with a significant contribution from the intrinsic Berry phase. This alloy also has a large room-temperature power factor (∼0.62 mWm-1K-2) and ultralow simulated lattice thermal conductivity (∼0.4 Wm-1K-1), making it a promising candidate for thermoelectric application. Ab initio calculations suggest weak spin-polarized semimetallic behavior and reduced magnetization (in agreement with the experiment) in the presence of DO3 disorder. We have also found an energetically competing ferromagnetic (FM)/antiferromagnetic interface structure within an otherwise FM matrix, one of the prerequisites for spin valve behavior. The coexistence of so many promising features in a single system is rare, and hence CoFeVSb gives a fertile platform to explore numerous applications in the future.
Volume
105
Publication link