Strong thickness dependence of aurivillius phase formation in SrBi2Ta2O9 thin films

• Published in: Journal of electroceramics Vol. 17; no. 2-4; pp. 119 - 123
• Main Authors: SUNG, Yun-Mo, KWAK, Woo-Chul, JUNG, Se-Yeon, NA, Jung-Joon, PARK, Sang M
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Heidelberg Springer 01.12.2006; Springer Nature B.V
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Condensed matter: structure, mechanical and thermal properties; Electrotechnical and electronic ceramics; Exact sciences and technology; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Technical ceramics; Thin film structure and morphology; Thin films; Scanning electron microscopy; SBT; Phase transformation, Thickness; Experimental study; X ray diffraction; Oxide ceramics; Thin film; Thickness; Thin films; Phase transformation; Ferroelectric; Ferroelectric materials; Sol gel process; Spin-on coating; Bismuth Strontium Tantalum Oxides Mixed; Manufacturing; Growth from solution; Tantalates; Electroceramics
• ISSN: 1385-3449; 1573-8663
• DOI: 10.1007/s10832-006-5651-7

Issue Title: Special Issue: ICE-2005 International Conference on Electroceramics Sr^sub 0.7^Bi^sub 2.4^Ta^sub 2^O^sub 9^ (SBT) thin films were studied for the dependence of Aurivillius phase formation kinetics on their film thickness. SBT thin films were fabricated using a sol-gel process and spin coating, and their thickness was varied controlling the number of spin coating. The films were first heated at a low temperature for the complete crystallization of amorphous film to fluorite phase and then further heated at different elevated temperatures for the phase transformation to Aurivillius for 40 min. It was found that the phase transformation kinetics apparently increased with thickness up to 390 nm, and then it sharply decreased at higher values. The Aurivillius crystal size decreased and the density of crystals increased with the increase of film thickness up to 390 nm, implying increasing number of nuclei due to the reduced energy barrier for nucleation. Above the critical value both the size and density of crystals decreased. It is suggested that up to 390 nm the tensile strain energy in the films, which was stored by the shrinkage of thin films during the removal of remaining organic components from sol-gel chemistry, plays a major role for determining the phase transformation kinetics and above the critical value SBT films act as a free bulk material without substrate constraints.[PUBLICATION ABSTRACT]