X-ray magnetic circular dichroism and photoemission studies of ferromagnetism in CaMnRuO thin films

X線吸収磁気円二色性測定と光電子分光によるCaMnRuO薄膜の強磁性の研究

寺井 恒太*; 吉井 賢資  ; 竹田 幸治   ; 藤森 伸一   ; 斎藤 祐児  ; 大和田 謙二; 稲見 俊哉; 岡根 哲夫  ; 有田 将司*; 島田 賢也*; 生天目 博文*; 谷口 雅樹*; 小林 啓介*; 小林 正起*; 藤森 淳*

Terai, Kota*; Yoshii, Kenji; Takeda, Yukiharu; Fujimori, Shinichi; Saito, Yuji; Owada, Kenji; Inami, Toshiya; Okane, Tetsuo; Arita, Masashi*; Shimada, Kenya*; Namatame, Hirofumi*; Taniguchi, Masaki*; Kobayashi, Keisuke*; Kobayashi, Masaki*; Fujimori, Atsushi*

We have studied the electronic and magnetic properties of epitaxially grown CaMnRuO thin films ( = 1.0, 0.75, 0.5) by soft X-ray absorption (XAS), soft X-ray magnetic circular dichroism (XMCD) and hard X-ray photoemission spectroscopy (HXPES) measurements. The XMCD studies indicated that the spin moments of Mn and Ru are aligned in opposite directions. The valence-band HXPES spectra revealed that the Ru 4 states around the Fermi level and the Mn 3 up-spin states centered 2 eV below it, both of which showed systematic concentration dependences. From these results, we propose that the localized Mn 3 states and the itinerant Ru 4 band are antiferromagnetically coupled and give rise to the ferromagnetic ordering, in analogy to the mechanism proposed for double perovskite oxides such as SrFeMoO.