In situ photoemission spectroscopic study on La 1− xSr xMnO 3 thin films grown by combinatorial laser-MBE

Abstract

We have performed an in situ synchrotron radiation photoemission spectroscopy (SRPES) on well-ordered surfaces of La 1− x Sr x MnO 3 ( x=0, 0.2, 0.4, 0.55) thin films grown using laser molecular beam epitaxy (laser-MBE). The laser MBE chamber is connected to a high-resolution SRPES system, where the grown films are transferred from the laser MBE to the SRPES chamber without breaking the ultrahigh-vacuum. In sharp contrast with the previous PES spectra recorded from scraped polycrystalline samples, the SRPES spectra exhibit an existence of prominent Mn 3d e g states near the Fermi level. On the other hand, O 1s X-ray absorption spectra for laser-MBE-grown samples are in good agreement with the scraped ones. These results clearly indicate the importance of in situ SRPES measurement on well-ordered surfaces of transition metal oxides for revealing their intrinsic electronic structures.