Normal–Diffuse Transition in (Pb,La)Zr0.53Ti0.47 Ferroelectric Ceramics

✍ Scribed by A. Peláiz Barranco; F. Calderón Piñar; O. Pérez Martínez

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 90 KB
• Volume: 220
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/1521-3951(200007)220:1<591::aid-pssb591>3.0.co;2-h

✦ Synopsis

PLZT compositions with a Zr/Ti ratio of 53/47 and variable lanthanum content (0.5 to 14 at%) have been investigated in their dielectric behaviors. The maximum value of the dielectric permittivity (e) and its temperature (T m ) decrease with increasing lanthanum concentration. The dielectric permittivity as a function of temperature can be described by a quadratic law above T m for PLZT x/53/47 (x ! 8at%) diffuse phase transition. Below this lanthanum content a Curie-Weiss behavior was obtained. Assuming a distribution of local Curie temperatures, the dielectric behavior could be correlated with the lanthanum concentration, i.e., the fluctuations of local Curie temperature values become more intense the larger the lanthanum content is. Analyzing the possible vacancy effects on the grain size morphology, the appearance of a diffuse phase transition with lanthanum addition could be explained.