Large tunnel magnetoresistance and temperature-driven spin filtering effect based on the compensated ferrimagnetic spin gapless semiconductor Ti2MnAl

Abstract

Spin gapless semiconductors, also known a special class of half-metallic magnets, have received more and more attention in spintronic applications due to the complete spin polarization and the electrical conductivity between half-metals and semiconductors. Motivated by the recent synthesis of spin gapless semiconductor Ti2MnAl with compensated ferrimagnetism (zero net magnetic moment) and high Curie temperature (above 650 K), we investigate the bias-voltage- and temperature-driven spin transport properties based on Ti2MnAl by using the density functional theory combined with nonequilibrium Green’s function method. A large tunnel magnetoresistance ratio (up to 2.8 × 106%), spin Seebeck effect, and temperature-driven spin filtering effect are found in the Ti2MnAl/InAs/Ti2MnAl(001) magnetic tunnel junction. These versatile transport properties suggest the potential applications for Ti2MnAl in spintronic devices and spin caloritronic devices.