Pinning and depinning mechanism of defect dipoles in PMnN–PZT ceramics

• Published in: Journal of physics. D, Applied physics Vol. 38; no. 8; pp. 1107 - 1111
• Main Authors: Li, BaoShan, Li, GuoRong, Yin, QingRui, Zhu, ZhiGang, Ding, AiLi, Cao, WenWu
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 21.04.2005; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Ferroelectricity and antiferroelectricity; Physics; Polarization; Frequency dependence; Inorganic compounds; Lead titanates; Transition element compounds; PZT; Lead zirconates; Defects; Ferroelectricity; Temperature effects; Coercive force; Dielectric hysteresis; Quaternary compounds
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/38/8/001

The frequency and temperature dependences of the hysteresis loops in Pb[(Zr0.52Ti0.48)0.95(Mn1/3Nb2/3)0.05]O3 ceramics have been investigated. The polarization-field hysteresis curves show 'pinched'shapes at room temperature and higher frequencies, whereas they display normal square-like loops at 200 deg C and frequencies lower than 10 mHz. Critical ferroelectric features such as the coercive field, polarization and internal bias field show a strong frequency or temperature dependence. The close relations between the P-E loops and the applied frequency and temperature indicate that the defect dipolar moment may change its magnitude with variation of the frequency or temperature. Comparing with the intrinsic depinning procedure induced by the changes in the distribution of defect dipoles, we provide new evidence for an extrinsic depinning mechanism of the defect dipoles in the bulk ceramics.