2018/02/20 by Raghuveer Chimata, Chimata, R., Erna K. Delczeg‐Czirjak +11
Materials Science · Physics and Astronomy · #Heusler alloys: electronic and magnetic properties #Magnetic properties of thin films #Shape Memory Alloy Transformations
paper · pdf · doi:10.48550/arxiv.1802.07195
By using a multiscale approach based on first-principles density functional theory combined with atomistic spin dynamics, we investigate the electronic structure and magnetization dynamics of an inverse Heusler and a Heusler compound and their alloys, i. e. Mn2-xZxCoAl and Mn2-xZxVAl, where Z = Mo, W, Os and Ru, respectively. A signature of the ferrimagnetic ordering of Mn2CoAl and Mn2VAl Heusler alloys is reflected in the calculated Heisenberg exchange constants. They decay very rapidly with the interatomic distance and have short range, which is a consequence of the existence of the finite gap in the minority spin band. The calculated Gilbert damping parameter of both Mn2CoAl and Mn2VAl is high compared to other half-metals, but interestingly in the particular case of the inverse Mn2CoAl alloys and due to the spin-gapless semiconducting property, the damping parameters decrease with the doping concentration in clear contradiction to the general trend. Atomistic spin dynamics simulations predict ultrafast magnetisation switching in Mn2CoAl and Mn2VAl under the influence of an external magnetic field, starting from a threshold field of 2T. Our overall finding extends with Heusler and inverse Heusler alloys, the class of materials that exhibits laser induced magnetic switching.