Magnetism of AlFeGeO with andalusite structure

柿本 和勇*; 高田 早紀*; 太田 寛人*; 原口 祐哉*; 萩原 雅人   ; 鳥居 周輝*; 神山 崇*; 三田村 裕幸*; 徳永 将史*; 畠山 温*; 香取 浩子*

Kakimoto, Kazuo*; Takada, Saki*; Ota, Hiroto*; Hayaguchi, Yuya*; Hagihara, Masato; Torii, Shuki*; Kamiyama, Takashi*; Mitamura, Hiroyuki*; Tokunaga, Masashi*; Hatakeyama, Atsushi*; Katori, Hiroko*

The magnetism of AlFeGeO from to with the andalusite structure was examined. AlFeGeO at low temperatures was found to show a weak ferromagnet-like behavior for and a spin glass behavior for . The small spontaneous magnetization observed in the weak ferromagnet-like samples may be caused by the existence of Dzyaloshinsky-Moriya interaction and the difference in the magnitude of the magnetic moments of Fe in the octahedral and trigonal bipyramidal sites. The appearance of the spin glass behavior implies that the dilution of Fe ions by Al ions in AlFeGeO causes the competition between ferromagnetic and antiferromagnetic interactions. The dependence of the site occupancy of Fe ions suggests that FeGeO with the andalusite structure cannot be synthesized.