Jitendra Pal Singh; Sanjeev Gautam; Braj Bhusan Singh; Sujeet Chaudhary; D. Kabiraj; D. Kanjilal; K. H. Chae; R. Kotnala; Jenn-Min Lee; Jin-Ming Chen; K. Asokan
Abstract
MgO based magnetic tunnel junctions (MTJs) exhibit high tunneling magnetoresistance (TMR) and have potential applications in magnetic random access memories. This study addresses the role of interface in the Fe/MgO/Fe based MTJs. For present investigation, Fe/MgO/Fe multilayer stack on Si substrates ...
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MgO based magnetic tunnel junctions (MTJs) exhibit high tunneling magnetoresistance (TMR) and have potential applications in magnetic random access memories. This study addresses the role of interface in the Fe/MgO/Fe based MTJs. For present investigation, Fe/MgO/Fe multilayer stack on Si substrates is grown by electron beam evaporation method and has been investigated for structural, magnetic and electronic properties. All the layers in the stack were of polycrystalline in nature as evidenced from X-ray diffraction studies, and the magnetic measurements show the attributes perpendicular magnetic anisotropy. Results from near edge X-ray absorption spectra at Fe L-edges measured by total electron yield mode and X-ray reflectometry indicate the formation of FeOx at the Fe/MgO interface. These are associated with hybridization of Fe (3d)-O(2p) levels at Fe/MgO interface in the stack and thickness of layers in the stacks. Absence of magnetic de-coupling between top and bottom ferromagnetic layers has been attributed to interface roughness and oxidation at Fe/MgO interface. This study highlights the role of interface and oxidation that need to be considered for improving the TMR for devices.
Jitendra Pal Singh; I. Sulania; Jai Prakash; S. Gautam; K. H. Chae; D. Kanjilal; K. Asokan
Abstract
Present work reports 200 MeV Ag 15+ irradiation induced effects on the surface morphology, grain size and local electronic structure in MgO thin films deposited by e-beam evaporation under ultra High vacuum. The grain size was found to decrease from 37 nm (pristine film) to 23 nm for the sample irradiated ...
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Present work reports 200 MeV Ag 15+ irradiation induced effects on the surface morphology, grain size and local electronic structure in MgO thin films deposited by e-beam evaporation under ultra High vacuum. The grain size was found to decrease from 37 nm (pristine film) to 23 nm for the sample irradiated with fluence of 1×10 12 ions/cm 2 and thereafter it increases upto fluence of 5×10 12 ions/cm 2 . Similar changes with ion fluence were also observed for surface roughness. Shifting and disappearance of peaks in X-ray absorption spectra with irradiation shows the electronic structure modification after irradiation. The detailed analysis of observed results has been done on the basis of existing theories.