An antiferro-to-ferromagnetic transition in EuTiO(3-x)H(x) induced by hydride substitution

Takafumi Yamamoto; Ryuta Yoshii; Guillaume Bouilly; Yoji Kobayashi; Koji Fujita; Yoshiro Kususe; Yoshitaka Matsushita; Katsuhisa Tanaka; Hiroshi Kageyama

doi:10.1021/ic502486e

An antiferro-to-ferromagnetic transition in EuTiO(3-x)H(x) induced by hydride substitution

Inorg Chem. 2015 Feb 16;54(4):1501-7. doi: 10.1021/ic502486e. Epub 2015 Jan 16.

Authors

Takafumi Yamamoto¹, Ryuta Yoshii, Guillaume Bouilly, Yoji Kobayashi, Koji Fujita, Yoshiro Kususe, Yoshitaka Matsushita, Katsuhisa Tanaka, Hiroshi Kageyama

Affiliation

¹ Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, and ‡Department of Material Chemistry, Graduate School of Engineering, Kyoto University , Nishikyo-ku, Kyoto 615-8510, Japan.

PMID: 25594721
DOI: 10.1021/ic502486e

Abstract

We have prepared the oxyhydride perovskite EuTiO(3-x)H(x) (x ≤ 0.3) by a low temperature CaH2 reduction of pyrochlore Eu2Ti2O7 and perovskite EuTiO3. The reduced EuTiO(3-x)H(x) crystallizes in the ideal cubic perovskite (Pm3̅m), where O/H anions are randomly distributed. As a result of electron doping by the aliovalent anion exchange, the resistivity of EuTiO(3-x)H(x) shows metallic temperature dependence. Moreover, an antiferromagnetic-to-ferromagnetic transition is observed even when a small amount of hydride (x ∼ 0.07) is introduced. The Curie temperature TC of 12 K is higher than those of any other EuTiO3-derived ferromagnets. The ferromagnetism can be explained by the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the Eu(2+) spins mediated by the itinerant Ti 3d electrons. The present study shows that controlling the oxide/hydride ratio is a versatile method to tune magnetic and transport properties.