ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Studies of the structure-property relations in Pb0.98Nb0.02- [(Zr1-xSnx)0.97Ti3]1-zO3 (PZST x/3/2) were performed for 0 〈 x 〈 0.50 by transmission electron microscopy, dielectric spectroscopy, and electrically induced polarization and strain methods. As the tin content increased, a general sequence of changes in phase stability was observed, including (i) a ferroelectric rhombohedral (FEr) phase (x 〈 0.15), (ii) a coexistence of FEr and antiferroelectric incommensurate (AFEin) states (x = 0.15), and (iii) an AFEin state (x 〉 0.15). Evidence will be presented that incommensurately modulated structures become pinned into long-lived metastable states by quenched tin impurities, rather than evolving toward a commensurate phase. Maximum electrically induced strains (epsilon) and polarizations (P) were found in the compositional range of x similar/congruent 0.15, where FEr and AFEin regions coexisted. Values of epsilon as large as 0.5% were found at field strengths of 〈80 kV/cm. In addition, these studies demonstrated evidence for two electrically induced phase transitions (x = 0.15): (i) an antiferroelectric-ferroelectric (AFE-FE) transition near 40 kV/cm, and (ii) a secondary ferroelectric-ferroelectric (FE-FE) transition near 60-80 kV/cm. The dominate contribution to epsilon was associated with the secondary transition, whereas the dominate contribution to P was associated with the first. For x 〈 0.15, evidence of an induced FE-FE transition was found. For x 〉 0.15, an induced AFE-FE transition was evident. However, no indications of a secondary FE-FE transition were observed. Large epsilon values were not induced until field levels significantly greater than that required to induced polarization saturation were obtained, which indicates a decoupling of epsilon and P.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.1998.tb02616.x
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