SrTiO_3単結晶基板上にエピタキシャル成長したFe薄膜の構造と磁気特性

摘要

Fe thin films were prepared on SrTiO_3(100), SrTiO_3(l 10), SrTiO_3(111) single-crystal substrates by UHV-MBE. The film growth structure and the magnetic properties were investigated. Fe epitaxial thin films with bcc structure were obtained on these SrTiO_3 substrates at elevated temperatures. The nucleation of bcc-Fe crystal on respective SrTiO_3 substrates varies depending on the substrate plane and the substrate temperature. The nucleation and growth of bcc-Fe film on SrTiO_3 substrates seems to be influenced by the strain and/or stress existing at the Fe/SrTiO_3 interface. The in-plane magnetic anisotropy measured for these epitaxial thin films reflects the magnetocrystalline anisotropy of bulk bcc-Fe crystal.%3種類の異なる結晶方位を持つSrTiO_3単結晶基板上でFe薄膜を形成し，Fe薄膜の構造と磁気特性を調べた．SrTiO_3（100），SrTiO_3（110），SrTiO_3（111），いずれの基板上においてもエビタキシヤルbcc-Fe薄膜が得られたが，Fe薄膜の核生成は基板結晶方位と基板温度に依存して多様に変化することが分かった．Fe薄膜の核生成はbcc-Fe結晶とSrTiO_3基板との界面に存在する歪や応力により影響されているものと解釈された．エピタキシャル成長したbcc-Fe薄膜の面内磁気異方性はバルクbcc-Fe結晶の結晶磁気異方性を反映している．