[10p-W323-1~16] 6.4 薄膜新材料

▲ [10p-W323-15] Preparation of TmFe₂O₄ Thin Films and Their Magnetic Properties

〇(D)YouJin Kim¹、Shinya Konishi¹、Yuichiro Hayasaka²、Katsuhisa Tanaka¹ (1.Kyoto University、2.Tohoku University)

キーワード：magnetic thin film, TmFe2O4

In this report, we present successful preparation of epitaxially grown TmFe₂O₄ thin films and their magnetic properties. This is the first report on the TmFe₂O₄ thin film to the best of our knowledge. TmFe₂O₄ thin films were epitaxially grown on yttria-stabilized zirconia (111) substrates by using a pulsed laser deposition method. Figure 1 shows the out-of-plane X-ray diffraction pattern of the resultant thin film, suggesting that the thin film wa epitaxially grown with c-axis orientation. The temperature dependence of magnetization (Fig. 2(a)) is similar to that reported for bulk polycrystalline TmFe₂O₄, but the observed Néel temperature is somewhat lowered. The magnetization almost linearly increases with an increase in magnetic field at 300 K as illustrated in Fig.2(b), suggesting that the thin film is likely paramagnetic at room temperature. Why the non-zero magnetization is observed at 300 K (Fig.2(a)) and the magnetic field dependence of magnetization (Fig.2(b)) manifests a deviation from the linear relation even at 300 K is not clear at this moment, but may be ascribable to magnetic impurity such as iron oxide and metallic iron with higher Curie temperatures. Another possible origin is the locally enhanced magnetic interactions at the interface between different layers contained in the present thin film, the structure of which was detected by our HAADF-STEM observations