Laboratory hard X-ray photoelectron spectroscopy of La_1-xSr_xMnO₃

A laboratory hard X-ray photoelectron spectroscopy (HXPS) system equipped with a monochromatic Cr Kα (hν = 5414.7 eV) X-ray source was applied to an investigation of the core-level electronic structure of La_1-xSr_xMnO₃. No appreciable high binding-energy shoulder in the O 1s HXPS spectra were observed while an enhanced low binding-energy shoulder structure in the Mn 2p_3/2 HXPS spectra were observed, both of which are manifestation of high bulk sensitivity. Such high bulk sensitivity enabled us to track the Mn 2p_3/2 shoulder structure in the full range of x, giving us a new insight into the binding-energy shift of the Mn 2p_3/2 core level. Comparisons with the results using the conventional laboratory XPS (hν = 1486.6 eV) as well as those using a synchrotron radiation source (hν = 7939.9 eV) demonstrate that HXPS is a powerful and convenient tool to analyze the bulk electronic structure of a host of different compounds.