Magnetic Tunnel Junctions Incorporating a Near-Zero-Moment Ferromagnetic Semiconductor

Abstract

In spintronics, the subfield of $s\phantom{\rule{0}{0ex}}p\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}n-o\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}b\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}s$ concentrates on exploiting both the spin and orbital magnetic properties of materials in, say, the electrodes of a magnetic tunnel junction (MTJ). Here a remarkable tunnel magnetoresistance as large as 200% is attained in MTJs based on SmN, an intrinsic ferromagnetic semiconductor with a very small magnetic moment that is dominated by orbital contributions. Uncommonly, this magnetoresistance is largest at $h\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}h$ fields, and at intermediate fields the SmN layer exhibits twisted magnetization.