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Acoustic Detection of Ferroelectric Phase Transitions in PLZT Ceramics
Author(s) -
KRAUSE J. T.,
O'BRYAN H. M.
Publication year - 1972
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1972.tb13414.x
Subject(s) - materials science , ferroelectricity , phase transition , ceramic , piezoelectricity , ferroelectric ceramics , lead zirconate titanate , phase (matter) , titanate , condensed matter physics , optoelectronics , composite material , dielectric , chemistry , physics , organic chemistry
Lanthanum‐doped lead zirconate‐titanate ferroelectric ceramics (PLZT) were tested acoustically using the pulse‐echo technique at 20 MHz. Phase transitions occurring within the range –269° to 300°C were detected in poled and unpoled Pb 1.02‐ x La x (Zr 0.65 Ti 0.35 )O 3 with x =0.00 to 0.15. For x =0.00 to 0.08 a phase transition observed between 0° and 100°C was defined by changes in the longitudinal sound velocity as great as 5% accompanied by pronounced absorption peaks. Measurements of resonance and electromechanical coupling in poled samples indicate that this transition involves 2 ferroelectric phases. The acoustic techniques reported made possible the detection of the subtler phase transitions in PLZT ceramics with a degree of sensitivity much higher than that available from the more conventional techniques. Both poled and unpoled samples may be tested by this technique, so that the influence of domain orientation on the transitions observed can be demonstrated.