1. An Antiferro-to-Ferromagnetic Transition in EuTiO3–xHx Induced by Hydride Substitution
- Author
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Katsuhisa Tanaka, Yoshitaka Matsushita, Ryuta Yoshii, Takafumi Yamamoto, Yoji Kobayashi, Koji Fujita, Guillaume Bouilly, Yoshiro Kususe, and Hiroshi Kageyama
- Subjects
Spins ,Hydride ,Inorganic chemistry ,Pyrochlore ,Oxide ,engineering.material ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Ferromagnetism ,chemistry ,Electrical resistivity and conductivity ,engineering ,Curie temperature ,Physical and Theoretical Chemistry ,Perovskite (structure) - 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.
- Published
- 2015
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