Effect of Processing on Synthesis and Dielectric Properties of Lead free (Bi0.98R0.02)0.5Na0.5TiO3 Ceramics

International Conference on Materials Science and Technology 2012

Pal, Vijayeta^1 ; Dwivedi, R.K.^1

Department of Physics and Material Science and Engineering, Jaypee Institute of Information Technology, Noida, UP

201307, India^1

关键词: Anti ferroelectrics;    Curie Weiss law;    Linear fitting;    Perovskite structures;    Precursor solutions;    Rhombohedral symmetry;    Temperature range;    Wet techniques;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/73/1/012121/pdf
DOI  :  10.1088/1757-899X/73/1/012121

来源: IOP

【 摘 要 】

In the present work, an effort has been made to synthesize (Bi1-xRx)0.5Na0.5TiO3 (BRNT) system with compositions x 0 & 0.02, where R La, Nd and Gd by Semi-Wet Technique. Processing of the composition with x 0 has been optimized by two precursor solution one by citric acid and other by ethylene glycol. The XRD patterns of these samples, prepared by ethylene glycol precursor solution, have shown pure phase of perovskite structure with a rhombohedral symmetry. The studies on structure, phase transitions and dielectric properties for all the samples have been carried out over the temperature range from RT to 450 °C at 100 kHz frequency. It has been observed that two phase transitions (i) ferroelectric to anti-ferroelectric and (ii) anti ferroelectric to paraelectric occur in all the samples. All samples exhibit a modified Curie-Weiss law above Tc. A linear fitting of the modified Curie- Weiss law to the experimental data shows diffuse type transition. The dielectric properties of BNT ceramics have been found to be improved with the substitution of rare earth elements.