Pseudo-single-crystal Cu underlayer (UL) with thermal tolerance was obtained on bare Si wafer by employing a diffusion-blocking layer. Fe4 N layer fabricated on the Cu UL has an epitaxial relationship and a large grain diameter. Magnetic tunnel junctions in a stacking sequence of Fe4 N/MgO/CoFeB exhibited an inverse tunnel magnetoresistance (TMR) effect at room temperature. The largest magnitude of the TMR ratio, -75.1%, was obtained at bias voltage Vb =-250 mV, where electrons flow from CoFeB to Fe4 N. The large inverse TMR ratio is due to the improvement of the crystallinity of the Fe4 N film because of the small lattice misfit between Fe4 N and Cu.
ASJC Scopus subject areas
- Physics and Astronomy(all)