Demonstration of reconfigurable magnetic tunnel diode and giant tunnel magnetoresistance in magnetic tunnel junctions made with spin gapless semiconductor and half-metallic Heusler alloy

Abstract

Here, we report fabrication of a high quality exchanged biased trilayer magnetic tunnel junction (MTJ) utilizing a magnetron sputtering system. The MTJ is composed of a type-II spin gapless semiconductor (SGS) Ti2CoSi inverse Heusler alloy (used as a lower electrode), a thin MgO layer (used as a tunnel barrier), and a half-metallic ferromagnet (HMF) Co2MnSi Heusler alloy (used as an upper electrode). Spin dependent transport properties reveal that the micro-fabricated MTJ can act as a reconfigurable magnetic tunnel diode, which lets the electric current to flow in either the forward or reverse path relying on the relative alignment of the magnetization direction of the upper and lower magnetic electrodes. A considerably high on/off current ratio (∼103) and a significantly low turn on voltage (VT) of 0.09 V have been achieved at 5 K for both parallel and antiparallel configurations. Another important characteristic shown by our fabricated MTJ is that it exhibits extremely large tunnel magnetoresistance ratios of 892% at 5 K and 197% at room temperature, which brings to light the utmost importance of using the combination of HMF and SGS materials as magnetic electrodes in a tunnel junction for potential applications in modern spintronic devices. All these exceptional features can undoubtedly nominate CMS/MgO/TCS MTJs as a promising candidate to serve as memory or logic elements in next generation ultra-high density magnetoresistive random access memories together with contemporary spin based electronic devices.

Spin-Gapless Semiconductors and Quantum Anomalous Hall Effects of Tetraazanaphthotetraphene-Based Two-Dimensional Transition-Metal Organic Frameworks on Spintronics and Electrocatalysts for CO2 Reduction

“…The SGS and semiconductor characteristics of M 3 (HHTT) 2 (M = Cr, Mn, and Cu) can be maintained at a biaxial strain from −6 to 6%, where the band gap increases at compressive strains and decreases at tensile strains, as shown in Figure S5. These results indicate that Cr 3 (HHTT) 2 and Cu 3 (HHTT) 2 are promising candidates in spintronics due to the 100% spin-polarization of the electrons and holes. , For example, the reconfigurable magnetic tunnel junction consists of an SGS electrode and an FM half-metal electrode, which exhibits a reconfigurable magnetic tunnel diode and giant tunnel magnetoresistance.…”

“…These results indicate that Cr 3 (HHTT) 2 and Cu 3 (HHTT) 2 are promising candidates in spintronics due to the 100% spin-polarization of the electrons and holes. 58,59 For example, the reconfigurable magnetic tunnel junction 60 consists of an SGS electrode and an FM half-metal electrode, which exhibits a reconfigurable magnetic tunnel diode 61 and giant tunnel magnetoresistance.…”

Resonant tunneling induced large magnetoresistance in vertical van der Waals magnetic tunneling junctions based on type-II spin-gapless semiconductor VSi2P4

“…[26][27][28] Recently, a septuple-atomic-layer 2D MA 2 Z 4 family (M is a transition metal, A is Si or Ge, and Z is N, P and As) consisting of one MZ 2 monolayer sandwiched between two AZ layers has become the focus of the research. [29][30][31][32][33][34][35][36][37][38][39] Cao et al found that the vdW MoSi 2 N 4 /NbS 2 contact exhibits an ultralow Schottky barrier height (SBH), and the SBH of MoSi 2 N 4 /graphene contact can be modulated via the interlayer interface or electric fields. 29 Wu et al researched the transport properties of the VSi 2 N 4 / MoSi 2 N 4 /VSi 2 N 4 MTJ and found that a large TMR and nearperfect spin injection efficiency appeared.…”

“…[36][37][38] The type-II SGS not only improves the efficiency of spin injection, but also implements new features, such as reconfigurable magnetic diode. 23,39,40 In particular, 2D MoSi 2 N 4 with high strength and excellent ambient stability has been successfully realized by a chemical vapor deposition method. 41 Based on this, in this work, we theoretically investigate the interface contacts, spin transport properties and TMR adjustments of vdW MTJs with VSi 2 P 4 as the ferromagnetic layers.…”