Effect of strain on the spin-polarization, mechanical and magnetic properties of Co2TiGe heusler alloy: A First Principle Study

Abstract

In our work, we studied the effect of isotropic strain from −6% to 8% (compressive to tensile) on the Band gap, Elastic, Spin-polarization and Magnetic properties of Co₂TiGe heusler alloy. We found that the half-metallicity (100% Polarization) is maintained under uniform strain from −2% to 4% but for the strain −4% to −6% the Spin-polarization drops quickly from 94% to 5.363%. From the study of electronic band structure we found that the energy band gap decreases with the increase of tensile strain and increase with the increase of compressive strain. For strain free compound the calculated magnetic moment of the material is 2.00 $\mu$B. We have found that under −4% to 8% uniform strain the total magnetic moment of the compound remains constant. But for strain −6% it decreases to 1.91 $\mu$B. We have calculated the mechanical properties of the material under different uniform strain. So, from the computed values we found the Bulk modulus, Young modulus, Shear modulus, Pugh’s ratio and Poisson ratio decreases with the tensile strain and increases with the compressive strain. With the increase of tensile strain (up to 8%) brittle nature of the material increases but with the increase of compressive strain (up to −6%) ductile of the material increases.