Strain effects on the electronic structures of Nd0.35Sr0.65MnO3 thin films studied by X-ray absorption spectroscopy

• Main Authors: Juo, Deng-Ming, 卓登明
• Other Authors: Huang, Di-Jing
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/54451836578803625566

碩士 === 國立交通大學 === 電子物理系所 === 103 === The rich physical properties of transition-metal oxides (TMO) arise from the strong coupling among the orbital, charge, spin and lattice degrees of freedom. Nd1-xSrxMnO3 is a perovskite-type doped manganite with a rich phase diagram and magnetic transitions as a function of doping concentration x. In addition, recent advances in the epitaxial growth and theoretical analysis expedite the research of the Nd1-xSrxMnO3 system. We performed the X-ray diffraction experiments to investigate the crystal structure of Nd0.35Sr0.65MnO3 thin films epitaxially grown on SrTiO3. The symmetry of Mn 3d orbitals is affected by the strain, which originates from the difference in the lattice structure between bulk Nd0.35Sr0.65MnO3 and SrTiO3 substrate. Furthermore, we measured polarization-dependent X-ray absorption spectra to study the electronic structure and orbital symmetry of Nd0.35Sr0.65MnO3 thin films. Our results reveal that the thin film of a thickness 40 nm exhibits a different eg orbital polarization in Mn3+ in comparison with that of a bulk sample. The difference of eg orbital polarization in Mn3+ is caused by the strain of the Nd0.35Sr0.65MnO3 thin film.