Synthesis and Characterization of PbZrTiO 3 Ceramics 62

Lead zirconate titanate (PZT) ceramic powders were prepared via conventional solid-state reaction method. The prepared samples were sintered at 900oC for 2 h. The sintered materials were characterized for structural analysis. The diffraction pattern reveals the pure phase formation of perovskite PZT structure. The morphology is analyzed by scanning electron microscope and average grain size is evaluated to be of 3.3 μm. The frequency and temperature dependence of electrical properties such as dielectric constant and dielectric loss was studied using LCR controller. In addition, the ferroelectric behavior was investigated by P-E loop tracer. Introduction. Lead titanate is a ferroelectric ceramic material. It shows distinct applications in various fields and is used for non volatile memories, medical ultrasound imaging and actuators and data storage devices [1, 2]. The well populated applications of ferroelectric materials are observed in the fields of dielectrics for capacitor applications. In particular, these materials are candidates for ferroelectric thin film technology. The perovskite materials will have a general chemical formula of the type ABO3 [2]. Many ferroelectric materials such as; barium titanate (BaTiO3), lead titanate (PbTiO3), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), have this perovskite type structure. These materials can work as good dielectric materials. In addition, the barium titanate, strontium titanate, strontium copper titanate, strontium lanthanum titanate, strontium lead titanate, strontium zinc manganese titanate, strontium magnesium titanate and strontium bismuth titanate are investigated recently for the dielectric and ferroelectric properties by several researchers [3-9]. In the current study, the structure, morphology, dielectric and ferroelectric behaviour are discussed for PZT ceramics. Experimental Procedure. In this study the precursors are chosen as PbO, ZrO2 (99.6% purity, Sigma Aldrich), TiO2 (99.4% purity, Sigma Aldrich) to prepare the ferroelectric PZT ceramics. Initially, the raw materials are weighed and mixed uniformly according to their stoichiometric ratio. The mixed powder is ball milled for approximately 12 h using ball miller (Retsch PM200. Furthermore, the uniformly grounded powder is pre-sintered at 700oC for 12 hr. The pre-sintered powder is again grounded for nearly 2 hr. The pellets of radius 0.58 cm and thickness 0.282 cm are prepared after applying 2 ton pressure using hydraulic press. The pellets are sintered at 850oC for 2 hr in conventional furnaces. Further, the pellets are characterized using XRD at room temperature (Bruker X-Ray Powder Diffract Meter, CuKα = 0.15418 nm), SEM (Hitachi: S-4700), LCR controller (Hioki 3532-50) and P-E loop measurement (Marine India) for structural, surface morphological, dielectric and ferroelectric properties respectively. Results and Discussions. © 2017 The Authors. Published by Magnolithe GmbH. This is an open access article under the CC BY-NC-ND license http://creativecommons.org/licenses/by-nc-nd/4.0/ Mechanics, Materials Science & Engineering, April 2017 – ISSN 2412-5954 MMSE Journal. Open Access www.mmse. xyz 359 Structural Analysis. The diffraction pattern of PZT ceramic powder is shown in Fig.1. It can be understood from figure that the formed single crystalline phases that belong to cubic perovskite structure of pure lead zirconate titanate. The maximum intense plane is noticed at the diffraction or two-theta angle of 32.254o. The value of lattice parameters ’c’ of PZT ceramic composition were found to be 4.131 Å where as “a = b” is 4.088 Å conforming the tetragonal perovskite structure. Furthermore, the average crystalline size (D) is calculated as 41.2 nm using the Scherer formula [1013]. Fig. 1. PZT perovskite structure. Fig. 2. SEM image of PZT. Surface Morphology. The Scanning Electron Microscope (SEM) provides the surface morphology of powder specimen. It is seen from Fig. 2 that all the grains are of almost spherical in shape. The average grain size (Ga) is found to be 3.3 μm using linear intercept method using the following equation [14].