[14p-A31-1~16] 6.3 Oxide electronics

[14p-A31-15] Metallic Surface States of CrO₂ (001) Films Observed by Depth-resolved Photoemission Spectroscopy

〇Hirokazu Fujiwara¹, Masanori Sunagawa¹, Tomoko Kittaka¹, Takanori Wakita², Kensei Terashima², Takanobu Nagayama¹, Makoto Ogata¹, Yuka Matsuura¹, Fumiya Yoshii¹, Shin-ichiro Ideta³, Kiyohisa Tanaka³, Yuji Muraoka^1,2, Takayoshi Yokoya^1,2 (1.Okayama Univ., 2.Research Inst. for Interdisciplinary Science, Okayama Univ., 3.UVSOR)

Keywords:half-metallic ferromagnet, surface, photoemission spectroscopy

CrO2 (001) film is a crucial material for application to spintronics devices due to its magnetocrystalline easy axis normal to the surface of the film. However, it is predicted that CrO2 (001) surface have insulating electronic states because of surface reconstructions. Also, it is well-known that the surface of CrO₂ tends to change into antiferromagnetic insulator Cr₂O₃, suffering us from observing the surface electronic states. In this study, we have prepared high quality CrO2 (001) films and performed depth-resolved photoemission spectroscopy measurements on the CrO2 samples in order to reveal the surface metallicity. We observed metallic surface electronic states, thus, we revealed that the (001) surface is metallic.