Co-Substitution Effect in Room-Temperature Ferromagnetic Oxide Sr3.1Y0.9Co4O10.5

Akihiro Tsuruta; Shuji Kawasaki; Masashi Mikami; Yoshiaki Kinemuchi; Yoshitake Masuda; Asaya Fujita; Ichiro Terasaki

doi:10.3390/ma13102301

Co-Substitution Effect in Room-Temperature Ferromagnetic Oxide Sr_3.1Y_0.9Co₄O_10.5

Materials (Basel). 2020 May 16;13(10):2301. doi: 10.3390/ma13102301.

Authors

Akihiro Tsuruta¹, Shuji Kawasaki^{1

2}, Masashi Mikami¹, Yoshiaki Kinemuchi¹, Yoshitake Masuda¹, Asaya Fujita¹, Ichiro Terasaki^{1

2}

Affiliations

¹ National Institute of Advanced Industrial Science and Technology (AIST), Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan.
² Department of Physics, Nagoya University, Furo-cho, Chuikusa-ku, Nagoya 464-8602, Japan.

Abstract

We investigated the Co substitution effect for the magnetic properties in room-temperature ferromagnetic oxide Sr_3.1Y_0.9Co₄O_10.5. The substituted element (Al and Ga) and low-spin state Co³⁺, which was changed from a high-spin or intermediate-spin state by Al or Ga substitution, reduced the Curie temperature to even 1.5 times lower than the temperature estimated from a simple dilution effect. Al³⁺ preferentially substituted for intermediate-spin-state Co³⁺ in the ferrimagnetic CoO₆ layer and deteriorated the saturation magnetization of Sr_3.1Y_0.9Co₄O_10.5. By contrast, Ga³⁺ substituted for high-spin-state Co³⁺ in the CoO₆ layer and/or the antiferromagnetic CoO_4.25 layer and enhanced the saturation magnetization per Co ion. These results indicate that the magnetic properties of Sr_3.1Y_0.9Co₄O_10.5 can be controlled by selectively substituting for Co³⁺ with different spin states.

Keywords: cobalt oxide; elemental substitution; room temperature ferromagnetism; spin state.