[10a-Z05-1~11] 6.4 薄膜新材料

▲ [10a-Z05-4] Structural and Magnetic Properties of Epitaxial TmFe₂O₄ Thin Film with Self-assembled Interface

〇(D)YouJin Kim¹、Shinya Konishi¹、Yuichiro Hayasaka²、Ryo Ota³、Katsuhisa Tanaka¹ (1.Kyoto Univ.、2.Tohoku Univ.、3.Hokkaido Univ.)

キーワード：hexagonal ferrite, exchange bias effect, spin glass

TmFe₂O₄, which is a member of the RFe₂O₄ family (R = Sc, Y, In, and Dy to Lu), manifests both charge and spin orderings and hence, interesting dielectric and magnetic properties are expected. We have grown epitaxial TmFe₂O₄ thin films on (111)-oriented yttria-stabilized zirconia (YSZ) substrates via a pulsed laser deposition method, and structural and magnetic properties were investigated by the scanning transmission electron microscopy with electron energy loss spectroscopy and magnetic measurements. Interestingly, the hexagonal TmFeO_3-δ phase has been found at the interface region between TmFe₂O₄ thin film and the YSZ substrate with the Tm³⁺-rich region at the upper side of the substrate. Furthermore, the intrinsic exchange bias effect was observed at 100 K by the spin competition between antiferromagnetic hexagonal TmFeO_3-δ and ferrimagnetic TmFe₂O₄ phases. We also found that TmFe₂O₄ itself exhibits a spin glass transition due to the strengthened magnetic frustration with oxygen off-stoichiometry.