D. Ramirez-rosales et al., Electron spin resonance study of the conversion of Mn4+ to Mn2+ in the Pb1-xEuxTi1-yMnyO3 ceramic system, SOL ST COMM, 118(7), 2001, pp. 371-376
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
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