Valence state of the manganese ions in mixed-valence La1−αBiβMn1+δO3±γ ceramics by Mn 2p and Mn 3s X-ray photoelectron spectra

► La1−αBiβMn1+δO3±γ (LBMO) ceramic samples are synthesized. ► Mn 2p and Mn 3s spectra are measured and calculated in an isolated-ion approximation with accounting for temperature effect. ► Both Mn3+ and Mn4+ ions are present in LBMO ceramics. ► Relative contents Mn3+/Mn4+ are determined.