文摘
We present the surface electronic and magnetic properties of half-metal La0.6Sr0.4MnO3 (LSMO) thin film modified by a simple cleaning procedure, the so-called SC1 (5 H2O, 1 NH4OH, 1 H2O2), at 85 掳C for 10鈥?0 min in ambient atmosphere. In this study, photoemission spectroscopy (XPS/UPS), X-ray absorption spectroscopy (XAS), and X-ray magnetic circular dichroism (XMCD) are used to characterize these properties of the manganites. Thanks to SC1 treatment, the work function of LSMO changes from 4.0鈥?.1 to 4.8鈥?.9 eV obtained from UPS measurements, while its surface roughness changes from 0.268 to 0.796 nm in AFM images. Combined O 1s, Mn 2p, Sr 3d, La 4d, and Mn 3s core-level XPS spectroscopy investigations suggest that Mn and Sr contents decrease at the surface and the Mn value becomes 3.7 due to SC1 treament. Mn L-edge XAS spectra of LSMO thin film demonstrate that SC1 treatment results in a removal of Mn2+ and an increase of the Mn4+ concentration. O K-edge XAS spectra further prove an enhancement of hybridization between O 2p orbitals and eg鈫?of Mn 3d induced by more Mn4+. XMCD results show that SC1 treatment does not induce any drastic changes of magnetic properties of the LSMO thin film surface.