Band-driven switching of magnetism in a van der Waals magnetic semimetal.

Matsuoka, Hideki; Kajihara, Shun; Nomoto, Takuya; Wang, Yue; Hirayama, Motoaki; Arita, Ryotaro; Iwasa, Yoshihiro; Nakano, Masaki · Sci Adv · 2024

basic_science · Level V

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Abstract

Magnetic semimetals form an attractive class of materials because of the nontrivial contributions of itinerant electrons to magnetism. Because of their relatively low-carrier-density nature, a doping level of those materials could be largely tuned by a gating technique. Here, we demonstrate gate-tunable ferromagnetism in an emergent van der Waals magnetic semimetal Cr<sub>3</sub>Te<sub>4</sub> based on an ion-gating technique. Upon doping electrons into the system, the Curie temperature (<i>T</i><sub>C</sub>) sharply increases, approaching near to room temperature, and then decreases to some extent. This non-monotonous variation of <i>T</i><sub>C</sub> accompanies the switching of the magnetic anisotropy, synchronously followed by the sign changes of the ordinary and anomalous Hall effects. Those results clearly elucidate that the magnetism in Cr<sub>3</sub>Te<sub>4</sub> should be governed by its semimetallic band nature.