International Journal of Innovative Science and Modern Engineering (IJISME) ISSN: 2319-6386, Volume-3 Issue-8, July 2015 11 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: H0918073815/2015©BEIESP Dielectric and Microstructural Properties of PbO Doped BaTiO 3 Shoumya Nandy Shuvo, Sujit Saha, Md. Miftaur Rahman Abstract:-The Barium Titanate (BaTiO 3 ) based ceramics has potential technological applications in multilayer Ceramics Capacitors (MLCC), thermistors, self-regulating electric heating system, transducers etc. The aim of the research is to find out the structural modifications and corresponding change in properties of BaTiO 3 when small amount of glass was added. Lead oxide (PbO) was used as glass for the doping which was in the powder form. In this research the effects of different level of PbO doping, sintering parameters and dielectric properties of PbO doped BaTiO 3 were observed and studied. At first, PbO was mixed with pure BaTiO 3 nanopowder at two different compositions by ball milling. Mixed powder was dried and after the addition of binder, the powder was pressed into pellets with the 5 ton pressure. After that, the green pellets were again dried. Then sintering was done at 800 0 C in a muffle furnace. After sintering, percentage theoretical density was measured. Then, using the ‘Precision Impedance Analyzer’, Dielectric constant, Dielectric loss and Capacitance were observed for the two different doping levels up to 10MHz frequency. Scanning electron microscopy (SEM) of the sample was then performed to observe the microstructural properties precisely. The result of the experiment was quite fascinating. It is found out that by modifying the sintering parameters and doping level of PbO with BaTiO 3 , better dielectric properties can be attained. Scanning Electron Micrograph indicates that by increasing the doping level of PbO, grain refinement is possible within 100nm range with precise uniformity. Keywords: Barium Titanate based ceramic, Nano-doping, Di-electric constant, Di-electric loss, Grain refinement I. INTRODUCTION Barium titanate is the harbinger of electronic ceramics which is obviously the first ferroelectric ceramics and a good candidate for a variety of applications due to its excellent dielectric, ferroelectric and piezoelectric properties [1]. In fact, the discovery of barium titanate led to a series of discoveries of many new ferroelectric substances, on which interesting studies, both experimental and theoretical, have been carried on. The discovery of barium titanate is most significant in that it is useful from the technological point of view [2,3] Barium titanate (BaTiO 3 ) is a very attractive material in the field of electroceramics and microelectronics due to its good characteristics. Revised Version Manuscript Received on July 15, 2015. Shoumya Nandy Shuvo, B.Sc. in Materials and Metallurgical Engineering, Department of Materials and Metallurgical Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh. Sujit Saha, B.Sc. in Materials and Metallurgical Engineering, Department of Materials and Metallurgical Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh. Md. Miftaur Rahman, Asst. Prof., Department of Materials and Metallurgical Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh. Its high dielectric constant and low loss characteristics make barium titanate an excellent choice for many applications, such as capacitors, multilayer capacitors (MLCs) and energy storage devices. Doped barium titanate has found wide application in semiconductors, positive temperature coefficient resistors, ultrasonic transducers, piezoelectric devices, and has become one of the most important ferroelectric ceramics [4,5]. Moreover the excellence of its piezoelectric properties is unsurpassed by any other piezoelectric material. Therefore, it is now beginning to be used for electro-mechanical transducers or electro-acoustic transducers and will surely gain very wide fields of application in future. The properties of BaTiO 3 have been the subject of study of many authors. It is well known that the properties of BaTiO 3 powders and ceramics strongly depend on the synthesis route and sintering regime. In this paper, the electric, dielectric and piezoelectric characteristics and applications of BaTiO 3 ceramics were studied. Despite the advantages offered by BaTiO 3 regarding small size capacitors their use is limited by number of operating variables [6]. The electric field strength and the operating temperature are strong determinants of dielectric constants. Dielectric properties also vary significantly up on the following factors: a) Size of individual grain and grain boundaries b) Presence and distribution of the impurity c) Stress imposed by surrounding grains d) Presence of second phase particle e) Condition of the material at the start of manufacturing f) Procedure of manufacturing and various processing variables [7,8] The dependence on temperature along with other properties such as the dielectric constants can be modified by forming solid solutions or doping the base perovskite with a range of composition. Successful attempts are made to substitute the atoms of perovskite from different lattice positions. e.g. the corner atoms or atoms positioned at the octahedral holes. For example, in BaTiO 3 ,Ba 2+ is replaced by Pb 2+ , Sr 2+ ions .Similarly the Ti 2+ is replaced by Zr 4+ , Hf 4+ [9-11]. Such doping brings certain modification to the structure of the perovskite which lead to versatility in the dielectric properties. Therefore, a considerable effort has been given to the development of best composition along with associated forming characteristics to improve the dielectric characteristics [12]. II. METHODOLOGY 1. Raw Materials and their characterization