R&D: Thermopower of Double-Barrier Magnetic Tunnel Junctions With Middle La_0.7Sr_0.3MnO₃ Layer

Physica Scripta (endorsed by The Royal Swedish Academy of Sciences) has published an article written by Reza Daqiq, physics, University of Malayer, Malayer, Iran.

Abstract: “Magnetic tunnel junctions (MTJs) are promising devices for heat-assisted magnetic recording (HAMR) technology. Quantum transport of nanoscale double-barrier MTJs with a middle La0.7Sr0.3MnO3 (LSMO) layer (DBMTJs-LSMO) is investigated by the non-equilibrium Green’s function (NEGF) formalism. The thermopower is described in the linear response regime. The results of the DBMTJs-LSMO show an enhancement of the thermopower compared to DBMTJs-CoFeB and conventional single-barrier MTJs (SBMTJs) due to the LSMO physical properties and also the existence of the quantum-well (QW) states. The parallel (P) and anti-parallel (AP) thermopower of S_P≈-225 μVK^(-1)and S_AP≈-320 μVK^(-1) are achieved at room temperature for DBMTJs-LSMO. The tunnel magneto-thermopower (TMT) ratio is found to be 42% at room temperature along with its maximum value of 138% at T=163 K for DBMTJs-LSMO.“