Hysteresis variations of (Pb, La,)(Zr, Ti)O-3 capacitors baked in a hydrogen atmosphere

Baking (Pb, La)(Zr, Ti)O-3 capacitors in a hydrogen atmosphere causes a sig nificant loss of remanent polarization even at 150 degrees C. The hysteresi s variations depend on the polarization states during baking. The hysteresi s loop showed voltage shifts when the capacitor was polarized before baking , whereas it became a cramped shape when the baking was carried out on a vi rgin capacitor. Although remanent polarization diminished in all cases, sat uration polarization was not suppressed. The clamped hysteresis loop can be described as an average of two loops shifted to positive and negative volt ages. The results indicate that the loss of remanent polarization is not du e to the suppression of switching, but due to the shift of the hysteresis o f each domain larger than the coercive voltage. (C) 1999 American Institute of Physics. [S0003-6951(99)04821-4].