Thermal analysis and phase evolution of ferroelectric PbTiO 3 obtained from silicate and borate based glasses Pat Sooksaen Æ Ian M. Reaney Received: 10 September 2007 / Accepted: 8 October 2007 / Published online: 4 December 2007 Ó Springer Science+Business Media, LLC 2007 Abstract This article assessed the glass formability for crystallization of lead titanate (PbTiO 3 ) as the primary phase. It was found that silicate-based glasses formed glass as a block without the need for cold splatting, but B 2 O 3 - based glasses needed to be prepared by cold splatting to retard devitrification. Also, incorporation of BaO was favoured by an increase in the concentration of B 2 O 3 . DTA showed the crystallization of crystalline phases occurred above glass transition temperature. XRD traces supported the DTA data where the first exothermic peak in each case was presumed to be related to the crystallization of PbTiO 3 (PT) phase. XRD also showed the lower c/a ratios com- pared to pure PT ceramic, which suggested three possibilities for lower values: crystal clamping by the rigid glass matrix, intrinsic size effect and incorporation of impurities in the PT phase. Introduction PbTiO 3 (PT) is a typical ferroelectric material with the perovskite structure. It undergoes a first-order phase tran- sition, T c * 490 °C above which the structure is cubic but below is tetragonal. The large ionic displacements in PT at T c lead to a particularly large room temperature spontaneous polarization ( [ 53 lC/cm 2 ), the largest in the perovskite family [1]. PT exhibits large pyroelectric coef- ficients, low relative permittivity (*100–200) and dielectric properties stable with time, temperature and frequency. These properties make PT an attractive material for pyroelectric and electro-optical applications [2–4]. Undoped PT is difficult to form as a ceramic body due to its large crystal anisotropy (c/a *1.06) and breaks into pieces on cooling below T c . This has limited the applications of undoped PT ceramics. The glass-ceramic route, therefore, offers the possibility of fabricating PT without cracking. Glass-ceramics are polycrystalline solids prepared by the controlled crystallization of glasses [5]. Many glass- ceramics have been investigated for use in the electronic industry due to advantages for preparing complex, large, fine-grained microstructures and pore-free bodies [6]. The applications include, for example [7–13], materials used in substrate applications, dielectric, pyroelectric/piezoelectric and optical devices. New glass forming techniques have led to a wide range of glass forming materials and as a result, new materials for a number of electronic applications are being fabricated. However, due to the limited number of published investigations the development in this area is still slow and a better understanding into the relationships between glass formation, crystallization, microstructure and electrical properties is still required. Studies relating to nucleation of high-permittivity fer- roelectric crystals in glasses have been carried out since the early 1960s. Ferroelectric crystalline phases investigated SrTiO 3 , BaTiO 3 , LiTaO 3 , LiNbO 3 , NaNbO 3 , KNbO 3 , PbTiO 3 , PZT, (Pb,Sr,Ba)Nb 2 O 6 [135] and strontium barium niobate (SBN) [14–24]. In this work, a series of glass compositions were melted and glass formation had been assessed for further compo- sitional modification. The crystallization to form PbTiO 3 P. Sooksaen (&) Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000, Thailand e-mail: pat@su.ac.th I. M. Reaney Department of Engineering Materials, Sir Robert Hadfield Building, University of Sheffield, Sheffield S1 3JD, UK 123 J Mater Sci (2008) 43:1265–1269 DOI 10.1007/s10853-007-2213-6