Anisotropic sensor and memory device with a ferromagnetic tunnel barrier as the only magnetic element

Abstract

Multiple spin functionalities are probed on Pt/La2Co0.8Mn1.2O6/Nb:SrTiO3, a device composed by a ferromagnetic insulating barrier sandwiched between non-magnetic electrodes. Uniquely, La2Co0.8Mn1.2O6 thin films present strong perpendicular magnetic anisotropy of magnetocrystalline origin, property of major interest for spintronics. The junction has an estimated spin-filtering efficiency of 99.7% and tunneling anisotropic magnetoresistance (TAMR) values up to 30% at low temperatures. This remarkable angular dependence of the magnetoresistance is associated with the magnetic anisotropy whose origin lies in the large spin-orbit interaction of Co2+ which is additionally tuned by the strain of the crystal lattice. Furthermore, we found that the junction can operate as an electrically readable magnetic memory device. The findings of this work demonstrate that a single ferromagnetic insulating barrier with strong magnetocrystalline anisotropy is sufficient for realizing sensor and memory functionalities in a tunneling device based on TAMR.

Spontaneous cationic ordering in chemical-solution-grown La2CoMnO6 double perovskite thin films

“…La 2 CoMnO 6 (LCMO) exemplifies the challenges associated with structure-property engineering of multicomponent oxide systems [8][9][10][11] . When full cationic ordering is achieved, LCMO is a ferromagnetic (FM) semiconductor with a relatively high FM Curie temperature, T C ≈ 230 K, making it very attractive for thermoelectric and spintronic applications 12,13 . FM ordering is explained by the superexchange interaction between Mn 4+ and Co 2+ according to the Goodenough-Kanamori rules [14][15][16] , and it is very sensitive to the cationic ordering in the B-sublattice 17 .…”

Tuning magnetic anisotropy in Co–BaZrO3 vertically aligned nanocomposites for memory device integration

“…Taking a typical group of spintronic devices as an example, magnetic tunnel junctions have received great interest due to their potential for application in high performance memory devices and various other applications. [7][8][9][10] Magnetic tunnel junctions typically consist of ferromagnetic lms that play pivotal roles in resistive switching. 11 To obtain higher resistive switching ratios and create more responsive magnetic tunnel junctions, extensive work has been done on tuning and fabricating ferromagnetic materials.…”

Magnetoresistance of Nanosized, Granular Sr2FeMoO6–δ–SrMoO4 Core–Shell Structures

“…MR calculations were performed based on Equation (12). The coefficient β was attributed in the study by López-Mir et al [28] to Zeeman splitting amounting about 1 μ B (1μ B % 0.058 meV T À1 ) for a magnetic field perpendicular and about 18 μ B for a magnetic field applied parallel to the current. In our case, the Fermi level of the down-spin states of SFMO is shifted up, while the levels of the SMO barrier remain constant.…”

“…The coefficient γ was determined from data in the study by López-Mir et al [28] yielding γ ¼ 0.034 meV T À2 . Note that the thickness of the La 2 Co 0.8 Mn 1.2 O 6 layer in the study by López-Mir et al [28] is in the order of the electron mean free path of a similar double perovskite. [32] This yields an anisotropy of MR and the tunneling current measured along film thickness direction with the field applied perpendicular and parallel to the sample.…”