Multiplet XPS analysis of the Mn 2p for Mn₃O₄ thin films

In this work, we performed a detailed analysis of the x-ray photoemission spectroscopy (XPS) of the Mn 2<i>p</i>peak for Mn₃O₄(001) thin films. This is a challenging task since Mn₃O₄is composed of two different cations, Mn²⁺at tetrahedral and Mn³⁺at octahedral sites, which both contribute to the XPS spectra. The oxide spectra consist of many multiplets arising from the angular momentum coupling of the open Mn 2<i>p</i>and 3<i>d</i>shells, thus increasing the spectrums' complexity. Moreover, the energy spacing and intensities of the different multiplets also reflect the covalent mixing between Mn 3<i>d</i>and O 2<i>p</i>shells. However, we show that a detailed analysis, which provides relevant information about the cations in the oxide structure, is possible. We prepared experimentally different Mn₃O₄films on Au(111), and their structure was monitored with the diffraction pattern obtained with low-energy electron diffraction. The Mn 2<i>p</i>spectra were fit, guided by cluster model theoretical predictions, and checked for films prepared at different oxygen partial pressures. Therefore, we could observe the Mn²⁺and Mn³⁺cations' relative concentration in the Mn 2<i>p</i>mains peaks.