A room-temperature magnetic semiconductor from a ferromagnetic metallic glass.

Liu, Wenjian; Zhang, Hongxia; Shi, Jin-An; Wang, Zhongchang; Song, Cheng; Wang, Xiangrong; Lu, Siyuan; Zhou, Xiangjun et al. · Nat Commun · 2016

basic_science · Level V

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Abstract

Emerging for future spintronic/electronic applications, magnetic semiconductors have stimulated intense interest due to their promises for new functionalities and device concepts. So far, the so-called diluted magnetic semiconductors attract many attentions, yet it remains challenging to increase their Curie temperatures above room temperature, particularly those based on III-V semiconductors. In contrast to the concept of doping magnetic elements into conventional semiconductors to make diluted magnetic semiconductors, here we propose to oxidize originally ferromagnetic metals/alloys to form new species of magnetic semiconductors. We introduce oxygen into a ferromagnetic metallic glass to form a Co<sub>28.6</sub>Fe<sub>12.4</sub>Ta<sub>4.3</sub>B<sub>8.7</sub>O<sub>46</sub> magnetic semiconductor with a Curie temperature above 600 K. The demonstration of p-n heterojunctions and electric field control of the room-temperature ferromagnetism in this material reflects its p-type semiconducting character, with a mobility of 0.1 cm<sup>2</sup> V<sup>-1</sup> s<sup>-1</sup>. Our findings may pave a new way to realize high Curie temperature magnetic semiconductors with unusual multifunctionalities.