Synthesis and Raman investigation of sol–gel-derived relaxor ferroelectric thin films

✍ Scribed by Ashok Kumar; R. S. Katiyar

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 342 KB
• Volume: 38
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/jrs.1765

✦ Synopsis

Abstract

Pb(Fe~2/3~W~1/3~)O~3~ (PFW) thin films were deposited on platinized silicon substrate by a chemical solution deposition technique. Room‐temperature X‐ray diffraction (XRD) revealed a pure cubic crystal structure of the investigated material. The microstructure indicated good homogeneity and density of the thin films. A Raman spectroscopic study was carried out on PFW to study the polar nano‐regions in the temperature range 85–300 K. The Raman spectra showed a change in the peak intensity and a shift towards the lower wavenumber side with temperature. The Raman spectra also revealed the transition from the relaxor to the paraelectric state of PFW. There was no evidence of a soft mode in the low‐temperature region, in contrast to the normal ferroelectric behavior. The polar nano‐regions tend to grow and join at low temperatures (∼85 K), which become smaller with increase in temperature. The presence of strong Raman spectra in the cubic phase of the material is due to the presence of distributed Fm__3__m(Z = 2) symmetry nano‐ordered regions in the Pm__3__m(Z = 1) cubic phase. Copyright © 2007 John Wiley & Sons, Ltd.