High-frequency electron paramagnetic resonance investigation of Mn3+ centers in SrTiO3

A high-frequency (49 and 70GHz) electron paramagnetic resonance (EPR) study is reported on SrTiO3 single crystals doped with 0.5-at% of manganese. EPR spectra originating from the S=2 ground state of Mn3+ ions are shown to belong to the different types of Jahn–Teller centers that arise as a result of varied ordering of the oxygen vacancies due to the reducing process. The present results indicate the strong covalent reduction of the density of unpaired spins (Fermi term) at the manganese nucleus for the various types of centers. [Display omitted] ► A high-frequency EPR study is reported on SrTiO3 single crystals doped with manganese. ► Different types of Mn3+ centers arise as a result of the ordering of the oxygen vacancies. ► EPR spectra show strong covalent reduction of the density of unpaired spins at the Mn nucleus.