Open AccessFinal Report: Stability and Novel Properties of Magnetic Materials and Ferromagnet / Insulator Interfaces
Author(s) -
Paul M. Voyles,
Y. Austin Chang
Publication year - 2013
Language(s) - English
Resource type - Reports
DOI - 10.2172/1088313
Subject(s) - materials science , spintronics , magnetoresistance , ferromagnetism , condensed matter physics , quantum tunnelling , fermi level , tunnel magnetoresistance , silicon , nanotechnology , optoelectronics , electron , magnetic field , quantum mechanics , physics
We report investigations of the synthesis, structure, and properties of new materials for spintronic applications integrated onto silicon substrates. Our primary focus is materials with very high, negative, intrinsic spin polarization of the density of states at the Fermi level. We have developed a new synthesis method for Fe3O4 thin films through selective oxidation of Fe, resulting in smooth, low-defect density films. We have synthesized Fe4N films and shown that they preferentially oxidize to Fe3O4. When integrated into magnetic tunnel junctions consisting of Fe4N / AlOx / Fe, oxidation at the Fe4N / AlOx interface creates Fe3O4, leading to negative tunneling magnetoresistance (TMR). Oxidation of Fe in nominally symmetric CoFe / AlOx / CoFe also produces Fe3O4 and negative TMR under selected oxidation conditions