Structural, electronic and magnetic properties of MnxGa/Co2MnSi (x = 1, 3) bilayers

Abstract

Directly coupled hard and soft ferromagnets were popularly used as the hybridized electrodes to enhance tunnel magnetoresistance (TMR) ratio in the perpendicular magnetic tunnel junction (pMTJ). In this paper, we employ the density functional theory (DFT) with general gradient approximation (GGA) to investigate the interfacial structure and magnetic behavior of tetragonal Heusler-type MnGa (MG)/L21-Co2MnSi (CMS) Heusler alloy bilayers with the MnGa being D022-MnGa alloy (Mn3Ga) and L10-MnGa alloy (MnGa). The MM-MS_B interface with the bridge (B) connection of MnMn termination (MM) of D022- and L10-MnGa layers to MnSi termination (MS) of CMS layers is found to be most stable in the energy point of view. Also, a strong antiferromagnetic coupling and relatively higher spin polarization can be observed in the MM-MS_B interface. Further, a remarkable potential difference to derive electrons to transfer from MG layer to CMS layer appears at the interface. These theoretical results indicate that the MG/CMS bilayers are promising candidates as coupled composites, and moreover, the D022-MG/CMS bilayer is better than L10-MG/CMS bilayer due to its larger spin polarization and built-in field at the interface.

Temperature-dependent spin polarization of Heusler Co2MnSi from the disordered local-moment approach: Effects of atomic disordering and nonstoichiometry

“…Different theoretical approaches have reported T C for L2 1 CMS as compared in Table II; [60,61], random-phase approximation (RPA) [60,62], and Monte Carlo (MC) simulation [63,64]. Among the MFA studies, reported results vary from 857 to 1162 K [57,60,61,65]. This may be caused by differences in computing exchange interactions, whose summation is required to calculate the T C , and/or in the DFT implementation.…”

“…The GGA and GGA+U methods were used in Refs. [65] and [57], respectively. Despite the differences in the T C of MFA results, we can see that the T C obtained from our DLM method shows the same magnitude and agrees well in particular with Ref.…”

“…The comparison of the Curie temperature, T C (in units of K), between theories and experiment for L2 1 and B2 Co 2 MnSi. In the literature values, the experimental lattice constant is used except for Refs [63][64][65],. where the equilibrium value is determined from the calculations.…”

Thermoelectric properties of flexible PEDOT:PSS-based films tuned by SnSe via the vacuum filtration method

“…20 Wang et al reported that the hybrid of high purity SiC-NWs with PEDOT:PSS obtained a high PF of 67.7 mW m À1 K À2 . 21 Recently, SnSe as a p-type TE material with an ultrahigh ZT of 2.6 AE 0.3 was reported by Zhao et al 22 and has shown prominent TE properties due to its high PF and ultralow k (ref. [23][24][25] and has been a promising composite candidate with non-toxic and lower cost.…”

IrCrMnZ (Z=Al, Ga, Si, Ge) Heusler alloys as electrode materials for MgO-based magnetic tunneling junctions: A first-principles study

“…Co 2 MnSi is reported as 985 K, although MFA shows the T C is about 1170 K [45,46]. In case of IrCrMnZ Heusler alloys, T C are very high.…”