[11a-M101-1~11] CS.9 10.1 新物質・新機能創成（作製・評価技術）, 10.2 スピン基盤技術・萌芽的デバイス技術, 10.3 スピンデバイス・磁気メモリ・ストレージ技術,10.4 半導体スピントロニクス・超伝導・強相関のコードシェアセッション

▲ [11a-M101-1] Resistive detection of the Néel temperature of Cr₂O₃ thin films

〇(M2)Tatsuya Iino¹、Takahiro Moriyama¹、Hiroyuki Iwaki¹、Hikaru Aono²、Yu Shiratsuchi²、Teruo Ono¹ (1.ICR, Kyoto Univ.、2.Osaka Univ.)

キーワード：spin Hall magnetoresistance, antiferromagnet, magnetic phase transition

Although bulk magnetic properties of various antiferromagnets have been vigorously studied since long ago, their properties in the form of thin films, which are more relevant to antiferromagnetic spintronic devices, have not been investigated as much. In this work, we characterized the Néel temperature of Cr₂O₃ thin films by investigating the temperature dependence of the spin Hall magnetoresistance (SMR) in Cr₂O₃/Pt bilayers.
We prepared Cr₂O₃/Pt bilayers epitaxially grown on a single crystal α-Al₂O₃substrate. We performed the resistance ratio measurements,between parallel and perpendicular to the magnetic field to sensitively detect the resistance change up on the magnetic phase transition. We employed Cr₂O₃ films with the magnetic easy axis parallel to the magnetic field. The drastic change in temperature dependence of (V₁/V₂)-1 around 300 K is associated with the resistance change due to SMR up on the magnetic phase transition and it corroborates the Néel temperature of Cr₂O₃ (cf. 307 K is reported for the bulk.). The results provide a reliable way to determine the Néel temperature of antiferromagnetic thin films.