Large room-temperature tunneling anisotropic magnetoresistance and electroresistance in single ferromagnet/Nb:SrTiO3 Schottky devices

Abstract

There is a large effort in research and development to realize electronic devices capable of storing information in new ways - for instance devices which simultaneously exhibit electro and magnetoresistance. However it remains a challenge to create devices in which both effects coexist. In this work we show that the well-known electroresistance in noble metal-Nb:SrTiO3 Schottky junctions can be augmented by a magnetoresistance effect in the same junction. This is realized by replacing the noble metal electrode with ferromagnetic Co. This magnetoresistance manifests as a room temperature tunneling anisotropic magnetoresistance (TAMR). The maximum room temperature TAMR (1.6%) is significantly larger and robuster with bias than observed earlier, not using Nb:SrTiO3. In a different set of devices, a thin amorphous AlOx interlayer inserted between Co and Nb:SrTiO3, reduces the TAMR by more than 2 orders of magnitude. This points to the importance of intimate contact between the Co and Nb:SrTiO3 for the TAMR effect. This is explained by electric field enhanced spin-orbit coupling of the interfacial Co layer in contact with Nb:SrTiO3. We propose that the large TAMR likely has its origin in the 3d orbital derived conduction band and large relative permittivity of Nb:SrTiO3 and discuss ways to further enhance the TAMR.

Surface anisotropy induced spin wave nonreciprocity in epitaxial La0.33 Sr0.67 MnO3 film on SrTiO3 substrate

“…1,2 Recently, perovskite LSMO is attracting more and more interest in the field of spintronics due to recent observations of the electric field tunability of the magnetoresistance, spin Seebeck effect, and critical temperature of magnetic phase transitions. [3][4][5][6][7][8][9][10] Moreover, epitaxial LSMO on a SrTiO 3 (STO) substrate is also attractive for the study of spin wave transmission [11][12][13][14] due to its low Gilbert damping 15 of a $ 10 À4 and low lattice mismatch with the substrate, which make it a promising candidate for a spin wave transmission study. 16 Spin waves possess interesting characteristics such as high-speed information processing due to their high frequency up to THz and their fairly low energy consumption due to the absence of charge current.…”

Electric field driven memristive behavior at the Schottky interface of Nb-doped SrTiO3

“…Recently, there has been a growing interest in understanding the rich and intricate properties of complex oxide interfaces and their application in superconductivity, magnetism and multiferroics [24][25][26][27]. The Schottky interface of Nb:STO offers rich electronic properties that have been shown to be useful both for memristor and spintronics applications [28][29][30][31]. An important parameter is the non-linear variation of the large dielectric permittivity ( r ) with temperature and electric field [32].…”

Band offsets at amorphous-crystalline Al2O3–SrTiO3 oxide interfaces

“…Motivated by this knowledge gap, we study the surface chemistry, electronic structure and relative band offsets at an amorphouscrystalline interface between Al2O3 and SrTiO3 (STO). This structure is further gaining recent attention as a tunneling junction in spintronic devices, 39,40 where better understanding of the electronic structure is expected to improve performance.…”