SUPEROXIDATION AND ELECTROCHEMICAL REACTIONS DURING SWITCHING IN PB(ZR,TI)O-3 CERAMICS

Under ferroelectric switching in Pb(Zr,Ti)O-3 (PZT) ceramics, me demon strate that oxygen gas is emitted and degrades electrode microstructur e, The oxygen is a direct result of the defect chemistry associated wi th superoxidation which is established during the processing of the ce ramics, Under high alternating electric fields, electron injection int o the ceramic surface induces a reduction process, and surface layers are believed to change from ap-type electronic compensation to an ioni c compensation of oxygen vacancies and A-site lead vacancies. During t his process, me noticed progressive changes in capacitance, loss, remn ant polarization, and coercive field, The wider implications of this o bservation for PZT thin film nonvolatile memories are discussed in bri ef.