title: An antiferro-to-ferromagnetic transition in EuTiO(3-x)H(x) induced by hydride substitution.
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.
authors.affiliation: 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.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Ryuta
authors.initials: R
authors.lastname: Yoshii
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bouilly
authors.forename: Yoji
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Koji
authors.initials: K
authors.lastname: Fujita
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Kususe
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Matsushita
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Tanaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kageyama