Abstract
In this work, the crystal structure and electronic property of the orthorhombic YMnO3 epitaxial film on YAlO3(010) substrate and Fe-doped YMnO_3 epitaxial film were studied by using X-ray diffraction (XRD), X-ray reflectivity (XRR), X-ray absorption spectroscopy (XAS) and anomalous X-ray diffraction. X-ray diffraction and X-ray reflectivity were measured at beamline BL07A, BL13A and BL17B in National Synchrotron Radiation Research Center (NSRRC). Due to the synchrotron radiation source has high intensity, excellent collimation and low emittance, those are suitable for analyzing the crystal structure and growth of the films. The thickness, roughness and arrangement of the films from X-ray reflectivity were analyzed by using GenX program. Because of the very similar scattering factors of Mn and Fe atoms, it is hard to distinguish these two atoms at specific sites of the structure from the change of diffraction peak intensity. Anomalous X-ray scattering was used to study the problem of the diffraction peak splitting of Fe-doped YMnO3 epitaxial film in (020) plane. The anomalous X-ray diffraction was performed at BL17B and XAS at BL16A. We change the incident X-ray energy to Mn K-edge (6.539 keV) and Fe K-edge (7.112 keV), then measure the (020) diffraction peak intensity. By comparing the anomalous X-ray diffraction with XAS, we calculate the scattering factor by using Kramers-Kronig relation. We found that the YMFO new sample had two phase and disorder structure. Another sample was YMFO old sample which was single phase. When we change the incident X-ray energy to Mn K-edge and Fe K-edge, the YMFO(010) forbidden diffraction intensity was enhanced 15 times to 20 times. The YMFO old sample was order structure.