Electron spin resonance study of the conversion of Mn4+ to Mn2+ in the Pb1-xEuxTi1-yMnyO3 ceramic system

Electron spin resonance (ESR) studies of the Pb0.88Eu0.08 Ti1-yMnyO3 (y = 0 .0, 0.1, 0.2, 0.3); PbTi0.98Mn0.02O3 and PbTiO3 ferroelectric ceramics are reported. The conversion of Mn4+ to Mn2+ in the Pb0.88Eu0.88Ti1-yMnyO3 cera mics compositions have been clearly demonstrated. The presence of the Eu ca tion is necessary for such conversion to take place and it does not take pl ace in the PbTi0.98Mn0.02O3 ceramic. Analysis of its ESR spectra indicates that Mn4+ substitution occurs at the Ti4+ at two different ESR-distinguisha ble locations. Both factors, namely the Mn4+ --> Mn2+ conversion and the Eu 3+ presence are responsible for the large microstrain and the deterioration of crystallinity observed in this ceramics, which seemed to play a crucial role for reading large piezoelectric anisotropy in the system. (C) 2001 El sevier Science Ltd. All rights reserved.