June 1999 Ž . Materials Letters 39 1999 318–323 www.elsevier.comrlocatermatlet X-ray, SEM and dielectric studies of Gd-modified sol–gel-prepared lead zirconate–lead titanate solid solution S.R. Shannigrahi, R.N.P. Choudhary ) , H.N. Acharya Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur 721 302, India Received 31 July 1998; received in revised form 12 January 1999; accepted 14 January 1999 Abstract Ž .Ž . Ž . Polycrystalline samples of Pb Gd Zr Ti O z s0.07, 0.08, 0.10 have been synthesized by an 1yz z 0.60 0.40 1yz r4 3 acetate–alkoxide sol–gel process. X-ray diffraction analysis suggests the formation of a single-phase material. The scanning Ž . electron microscopy SEM study shows the uniform distribution of grains in the samples. Detailed dielectric studies of the Ž . 3 4 compounds, as a function of temperature from 308C to 4508C at 10 Hz and 10 Hz, show that the compounds undergo a Ž . diffuse phase transition. Diffusivity g study of phase transition of these compounds provides its value between 1 and 2, indicating the variation of degree of disordering in the system. The value of remanent polarization and coercive field decrease with increase of Gd ion concentration. q 1999 Elsevier Science B.V. All rights reserved. Keywords: Gd; Sol–gel; PZT 1. Introduction Since the early 1950s, lead zirconate–lead titanate Ž . solid solutions PZTs have become the subject of extensive research because of their wide industrial w x importance 1,2 . It has also been found that La-mod- Ž . ified PZT PLZT near the morphotropic phase Ž . boundary MPB has very promising piezoelectric wx properties for device fabrication 3 . In most of the complex PLZT compounds, broadened dielectric peaks or diffuse phase transitions have been ob- wx served 4 . The transition is smeared out over a certain temperature interval, resulting in a gradual change in physical properties in this temperature ) Corresponding author interval, which is due to compositional, and polarisa- wx tion fluctuations 5 . In order to have a better esti- mate of the degree of disordering of phase transitions and of changes in physical or device parameters Ž . of Gd-doped PZT of composition Pb Gd 1yz z Ž . Ž .Ž . Zr Ti O z s 0.07, 0.08, 0.10 PGZT , 0.60 0.40 1yz r4 3 we have examined their structural, dielectric and hysteresis properties. 2. Experimental Polycrystalline samples of composition PGZT were prepared from the raw materials: lead acetate Ž . Ž trihydrate Pb CH COO P 3H O 99.999%, Mrs. 3 2 2 . E. Merck, Germany , gadolinium acetate tetrahy- Ž . Ž drate CH COO Gd P 4H O 99.9%, Mrs. Aldrich, 3 3 2 . Ž . Ž USA , zirconium propoxide Zr C H O 99.99%, 3 7 4 00167-577Xr99r$ - see front matter q 1999 Elsevier Science B.V. All rights reserved. Ž . PII: S0167-577X 99 00027-0