Micro-Raman spectroscopic investigation of rare earth-modified lead zirconate titanate ceramics

2007 ◽  
Vol 33 (4) ◽  
pp. 595-600 ◽  
Author(s):  
S.R. Shannigrahi ◽  
S. Tripathy
Author(s):  
M.L.A. Dass ◽  
T.A. Bielicki ◽  
G. Thomas ◽  
T. Yamamoto ◽  
K. Okazaki

Lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), ceramics are ferroelectrics formed as solid solutions between ferroelectric PbTiO3 and ant iferroelectric PbZrO3. The subsolidus phase diagram is shown in figure 1. PZT transforms between the Ti-rich tetragonal (T) and the Zr-rich rhombohedral (R) phases at a composition which is nearly independent of temperature. This phenomenon is called morphotropism, and the boundary between the two phases is known as the morphotropic phase boundary (MPB). The excellent piezoelectric and dielectric properties occurring at this composition are believed to.be due to the coexistence of T and R phases, which results in easy poling (i.e. orientation of individual grain polarizations in the direction of an applied electric field). However, there is little direct proof of the coexistence of the two phases at the MPB, possibly because of the difficulty of distinguishing between them. In this investigation a CBD method was found which would successfully differentiate between the phases, and this was applied to confirm the coexistence of the two phases.


2004 ◽  
Vol 830 ◽  
Author(s):  
Hiroshi Nakaki ◽  
Hiroshi Uchida ◽  
Shoji Okamoto ◽  
Shintaro Yokoyama ◽  
Hiroshi Funakubo ◽  
...  

ABSTRACTRare-earth-substituted tetragonal lead zirconate titanate thin films were synthesized for improving the ferroelectric property of conventional lead zirconate titanate. Thin films of Pb1.00REx (Zr0.40Ti0.60)1-(3x /4)O3 (x = 0.02, RE = Y, Dy, Er and Yb) were deposited on (111)Pt/Ti/SiO2/(100)Si substrates by a chemical solution deposition (CSD). B-site substitution using rare-earth cations described above enhanced the crystal anisotropy, i.e., ratio of PZT lattice parameters c/a. Remanent polarization (Pr) of PZT film was enhanced by Y3+-, Dy3+- and Er3+-substitution from 20 μC/cm2 up to 26, 25 and 26 μC/cm2 respectively, while ion substitution using Yb3+ degraded the Pr value down to 16 μC/cm2. These films had similar coercive fields (Ec) of around 100 kV/cm. Improving the ferroelectric property of PZT film by rare-earth-substitution would be ascribed to the enhancement of the crystal anisotropy. We concluded that ion substitution using some rare-earth cations, such as Y3+, Dy3+ or Er3+, is one of promising technique for improving the ferroelectric property of PZT film.


2001 ◽  
Vol 84 (12) ◽  
pp. 2921-2929 ◽  
Author(s):  
Alexandre E. Glazounov ◽  
Hans Kungl ◽  
Jan-Thorsten Reszat ◽  
Michael J. Hoffmann ◽  
Arnd Kolleck ◽  
...  

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