Barium Strontium Titanate Lab Report

Abstract
The present study, considering Barium strontium titanate due to its important applications in the electronic device as the piezoelectric material due to excellent performance as sensing and actuation. Barium strontium titanate nanocrystalline ceramic have been synthesized from mechanical alloying of commercially available BaCO3, SrCO3 and TiO2 by high energy ball milling. This method has produced nano-sized particles as well as highly reactive surface, can cause structural relaxation of surface atom and produce inhomogeneous strain by producing defect in crystalline solids and that defect can influence powder properties. The milled powders are characterized at different stages of milling by XRD, particle size analyzer, FESEM
This structural transformation gradually reduces the dielectric behavior of the Barium strontium titanate at nano scale. It was observed that Capacitance drastically reduced from 20.47 pF to 3.06 pF.

Keywords: Sr-doped Barium Titanate powders, Structural ordering disordering, Phase transformation, heating, Particle size, Dielectric properties

1. INTRODUCTION
Since Barium Titanate has a wide range of applications as ceramic capacitors, it has important industrial applications.[1-3] Also, recent technological trend towards the decreasing dimension makes BaTiO3 interesting material to experiment at the nano scale. However, the properties of some materials at nano scale may have significant change when the particle size deducted to nano range. The addition of proper dopant can also give us attractive materials for applications in power engineering or medical device technology, electronic devices (such as capacitors). [4-6]. BaTiO3 has also significance as the only lead (Pb) free ferroelectric and free from hydrogen bonding which undergoes a several numbers of phase transformation as the function of force and
Our main motive was to prepare Sr-doped BaTiO3 by mechanochemical milling effect. These three type of samples were mixed and milled in the planetary mono-mill machine (Pulverisette 6, FRITSCH, Germany)in order to particle size reduction[15]. The milling process was continued for 0-150 hours at 200 rpm constant speed in a tungsten carbide (WC) pot of capacity 80 ml. 40 gms of the mixture (18.20 gms BaCO3, 12.32 gms SrCO3, 9.48 gms TiO2) are milled with help of two WC balls of diameter 20 mm. The samples were taken at different intervals for structural characterization by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Particle Size Analysis and Dielectric Property Measurement. The X-ray diffraction patterns of the milled mixture powders, both calcined (1200° C) and uncalcined were recorded in X’pert Pro MPD diffractometer (PANalytical) using X’Celerator, which operates at 40 kV and 30 mA, using Ni- filtered CuKα radiation. The XRD data were recorded with a step size of 0.020 (2u) and step time of 75 seconds for the samples of different hours milled samples and FESEM images were recorded through Zeiss microscope (Zeiss, UK, Model: SUPRATM 35Vp) of calcined samples.[16] Calcination at 1200°C is done for eliminating the carbons, present in the mixtures. Since both BaCO3, SrCO3 have very stable