Tunneling Magnetoresistance In Iron (Fe) / Topological Insulator / Iron (Fe).

Abstract

Tri-layer thin films of iron (Fe) with topological insulator (TI) as a buffer, Fe/TI/Fe was synthesized using magnetron DC/RF sputtering on MgO (100) substrate at a substrate temperature of 100°C with Bi2Te3. The topological insulator, used as a buffer layer is Bi2Te3. The multilayered samples thus produced were studied using an in-house built magneto-optic Kerr effect (MOKE) instrument, vibrating sample magnetometer (VSM), magnetic force microscopy (MFM), and torque magnetometer (TMM). Further analysis was made by probe measurements and Physical Property Measurements System (PPMS) to measure electrical conductivity properties. This system that is Fe/TI/Fe on MgO (100) substrate is a tunnel magnetoresistance (TMR) structure and used in magnetic tunnel junction (MTJ) devices. TMR effect is a phenomenon whereby MTJs have applications such as magneto-resistive random access memory (MRAM), magnetic sensors, and logic devices. The purpose of this research is to measure the magnetic anisotropy of Fe/TI/Fe structural properties and correlate it to magneto-resistance. In this thesis, results from MOKE, VSM, MFM, TMM, and magnetoresistance measurements will be presented with study on Fe/ Bi2Te3 /Fe /MgO(100) synthesized at 100°C. In this structure Fe/TI/Fe each Fe layer is 50 nm thick and the TI is 5mm.