Tunneling Magnetoresistance (TMR) On Fe-A1203 Nano Granular Film Growth By Helicon Plasma Sputtering

Abstract:

Fe-Al₂O₃ nanogranular thin film  by helicon plasma sputtering  with the variation of Fe content from 0.1 to 0.7 volume fraction have been prepared. The magnetic and magnetoresistance properties were investigated by a Vibrating Sample Magnetometer (VSM) and a Four Point Probe (FPP).  

The Rutherford BackScattering (RBS) was performed with the SIMNRA software. Conversion Electron Mossbauer Spectroscopy (CEMS) study was also performed to estimate the fraction of Fe and α-Fe₂O₃ in the granular film. The results suggested that the percolation concentration occured at 0.55 Fe volume fractions, with the maximum Magnetoresistance (MR) ratio of 3%.  The present MR ratio that was lower than the previous results  may be related to the existence of α-Fe₂O₃ phase.

Keyword: Nanogranular thin film; Helicon plasma sputtering; Tunneling magnetoresistance; Conversion electron mossbauer spectroscopy; Rutherford back scattering (RBS)

S Purwanto

Center For Technology of Nuclear Industry Materials National Nuclear Energy Agency (BATAN) Puspiptek Area, Serpong, Tangerang, Indonesia