Multiplet XPS analysis of the Mn 2p for Mn<sub>3</sub>O<sub>4</sub> thin films
Jade Barreto, Paul S. Bagus, Fernando Stavale
Abstract
Abstract In this work, we performed a detailed analysis of the x-ray photoemission spectroscopy (XPS) of the Mn 2 p peak for Mn 3 O 4 (001) thin films. This is a challenging task since Mn 3 O 4 is composed of two different cations, Mn 2+ at tetrahedral and Mn 3+ 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 p and 3 d shells, thus increasing the spectrums’ complexity. Moreover, the energy spacing and intensities of the different multiplets also reflect the covalent mixing between Mn 3 d and O 2 p 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 Mn 3 O 4 films on Au(111), and their structure was monitored with the diffraction pattern obtained with low-energy electron diffraction. The Mn 2 p spectra were fit, guided by cluster model theoretical predictions, and checked for films prepared at different oxygen partial pressures. Therefore, we could observe the Mn 2+ and Mn 3+ cations’ relative concentration in the Mn 2 p mains peaks.