Electron paramagnetic resonance (EPR) and static magnetic susceptibility measurements were carried out on lanthanum-manganese substituted (up to 10 mol%) strontium titanate polycrystalline samples. X-ray diffraction (XRD) analysis revealed in each sample a single cubic perovskite phase with a different lattice parameter. Only weak and narrow EPR signals from a small fraction of Mn2+ and Mn4+ ions were observed when the La and Mn content did not exceed 5 mol%, indicating the nearly complete stabilisation of the Mn3+ oxidation state. Heavily substituted samples showed another EPR signal, very broad and with intensity and resonance field strongly temperature dependent. For these samples, a complex dynamics of Mn3+ stabilisation is suggested, supported by micro-Raman data
Magnetic investigation of Mn ions in La,Mn:SrTiO3
AZZONI, CARLO;MOZZATI, MARIA CRISTINA;GALINETTO, PIETRO;MASSAROTTI, VINCENZO;BINI, MARCELLA;CAPSONI, DORETTA
2000-01-01
Abstract
Electron paramagnetic resonance (EPR) and static magnetic susceptibility measurements were carried out on lanthanum-manganese substituted (up to 10 mol%) strontium titanate polycrystalline samples. X-ray diffraction (XRD) analysis revealed in each sample a single cubic perovskite phase with a different lattice parameter. Only weak and narrow EPR signals from a small fraction of Mn2+ and Mn4+ ions were observed when the La and Mn content did not exceed 5 mol%, indicating the nearly complete stabilisation of the Mn3+ oxidation state. Heavily substituted samples showed another EPR signal, very broad and with intensity and resonance field strongly temperature dependent. For these samples, a complex dynamics of Mn3+ stabilisation is suggested, supported by micro-Raman dataI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
