Electronic structure of strained(La0.85Ba0.15)MnO3thin films with room-temperature ferromagnetism investigated by hard x-ray photoemission spectroscopy

We report the bulk sensitive hard x-ray $(h\ensuremath{\nu}=5.95\phantom{\rule{0.3em}{0ex}}\mathrm{keV})$ core level photoemission spectroscopy to investigate the intrinsic electronic structure of strained $({\mathrm{La}}_{0.85}{\mathrm{Ba}}_{0.15})\mathrm{Mn}{\mathrm{O}}_{3}$ thin films. In a $20\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ thick well-strained film with strongly enhanced ferromagnetism, a new sharp satellite peak appeared at the low energy site of the Mn $2{p}_{3∕2}$ main peak; whereas, a broader signal was observed for the unstrained film with $300\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ thickness. Cluster calculations revealed that the intensity corresponded to the density of the state at the Fermi level relating to the magnitude of the ferromagnetic order. The satellite intensity also agreed quantitatively with the square of the magnetization.