Non-MgO materials as alternative barriers in magnetic tunnel junctions for spintronics applications
Dr. Mohamed Bel Moubarik,
Institute of Applied Physics, UM6P
IAP Physics Seminar Series will occur on Tuesday 25 June, at 15:15 at the UM6P campus (Ryad 8, 1st floor).
Abstract:
The utilization of a ferromagnet (FM)/oxide/FM trilayer structure in a magnetic tunnel junction (MTJ) is essential for spintronic devices, particularly in magnetic read sensors for hard disk drives and magnetic memory cells employed in magnetoresistive random access memories (MRAMs). The performance of an MTJ, measured by the tunnel magnetoresistance (TMR) ratio, undergoes significant changes based on the materials used for the FM electrode and barrier, as well as their lattice-mismatch and crystal orientation relationship. Remarkably high TMR ratios are observed in MTJs featuring a (001)-oriented crystalline barrier, such as MgO[1] and MgAl2O4 [2–4] (spinel), owing to the spin-dependent coherent tunneling mechanism. This talk provides an overview of recent advancements in epitaxial MTJ barrier technologies utilizing MgO and spinel-based oxides. Additionally, it emphasizes the advantages of spinel-based barriers for future MTJ applications, including favorable lattice-matching with diverse FM electrodes and the tunability of barrier properties through compositional optimization. The discussion will cover four main spinel oxides with different bandgaps (MgAl2O4 ZnAl2O4, MgGa2O4 and Ga2O3) [5–7] and the fabrication challenges to release high-quality MTJs devices for various spintronics applications. Also (111)-FM/hcp-(Mg,Zn)O/(111)-FM-based MTJs, as a source of perpendicular magnetic anisotropy, will be introduced [8–10]. These alterative tunnel-barriers might offer a better understanding of the spin-dependent tunneling phenomenon and present new pathways to solve technological challenges of the conventional MgO-based MTJs.
Biography:
Dr BEL MOUBARIK completed his PhD from Tohoku university, Japan in 2014 with a specialization in spintronics and materials science. He challenged the fabrication of new types (111)-oriented metallic based magnetic tunnel junctions (MTJs) as an alternative of the conventional (001) MgO-MTJs and succeeded in publishing a few good papers at prestigious journals (Applied Physics Letters and Physical Review B). Then, he joined NIMS Japan (2015-2017) as a scientific researcher for the Japan governmental project for industry-oriented and high-risk innovation called “ImPACT” in collaboration with many industrial partners in magnetic storage. He worked closely with talented researchers in materials science and spintronics for the finding and implementation of alternative barrier materials (such as spinel oxides and hcp-ZnO) within MTJs, the main block of nowadays spintronics. From late 2017, he moved to INL, Portugal for another challenge targeting the improvement of MTJs-based magnetoresitive sensors by engineering the properties of their magnetic materials. Importantly, he received three competitive grants from JSPS Japan and EU-Horizons 2020, participated in filling three patents, and disseminated his research output in conferences and peer reviewed papers.
Localization: Ryad 8, 1st Floor.