[13a-2J-1~11] 10.1 新物質創成（酸化物・ホイスラー・金属磁性体等）

▼ [13a-2J-3] Detection of Neel temperature and blocking temperature in an exchange coupled system with ultrathin (≤20nm) Cr₂O₃ film

〇(P)Satya Pati¹, Tomohiro Nozaki¹, Masashi Sahashi¹ (1.Tohoku University)

キーワード：Magnetoelectric,Thermal Stability,Spintronics

Future spintronics of high density recording media demands the fabrication of high quality, continuous ultrathin Cr₂O₃ for low voltage operation. However, thermal stability of the device will decrease by using a ultrathin Cr₂O₃ due to decrease of Néel temperature (T_N) and antiferromagnetic (AF) anisotropy by scaling effect. Recently, there are some sincere efforts by researchers to give a direction towards enhancement of thermal stability in magnetoelectric Cr₂O₃ [1-2]. One of the approaches to enhance T_N is spin correlation effect, where by forming a laminated structure with Fe₂O₃, the length of antiferromagnetic spin correlation increases more than twice of the bulk as proposed by Kota et al [2]. However, this enhanced antiferromagnetic spin correlation length persists upto several monolayer. Hence effective use of spin correlation effect is again required to fabricate ultrathin Cr₂O₃ having AF ordered. Another problem is the detection of T_N of ultrathin film, as with decreasing thickness Cr₂O₃ loses its long range antiferromagnetic ordering.In this work, we report the detection exchange bias of sample comprising 5nm of Cr₂O₃ at low temperature and T_N of 1nm Cr₂O₃.