Determinação da formação de Titanato de Chumbo dopado com Gadolínio via Pechini por Difratometria de raios–x

Abstract

Perovskite is a mineral that has been widely researched scientifically because it is a compound that can possess magnetic and electrical properties at the same time. However, such materials are difficult to synthesize, they have not been consolidated in the literature and they are often expensive to produce. Thus, one solution for synthesizing perovskite minerals with both properties is to dope a compound that has one of these properties with a different metal that can give this material the other desired property. In this context, the purpose of this research was to investigate the doping of lead titanate, PbTiO3, a perovskite with electrical properties, with the addition of gadolinium, a rare earth metal with magnetic properties. According to Acikgoz et al. (2023), the addition of small amounts of Gadolinium to the titanate structure without the restriction of oxygen in the synthesis forms the most stable crystal Pb(2-3x)/2GdxTiO3. This crystal maintains the perovskite structure, the properties of PbTiO3 and acquires paramagnetic properties due to the presence of gadolinium in the structure. The synthesis of two compounds, PbTiO3 and Pb0.895Gd0.07TiO3, and the calculation of the particle sizes obtained, the targets of this work, they were carried out using the methodology developed by Pechini (1967), with the use of standards obtained from the Inorganic Chemistry Structure Database, ICSD. The data obtained from the modeling via GSAS-II was processed in Origin. Pro 9, on mathematical models found in the book by Cullity and Stock (2014) and it went through mathematical modeling developed by Willianson and Hall, WH-Plot and the use of the methodology developed by Willianson and Hall, WH-Plot, in conjunction with the least squares linear regression method. The material was synthesized using titanium isopropóxido, lead and gadolinium nitrates, citric acid, ammonium hydroxide, ethylene glycol and methanol. The compound was synthesized in an acidic medium with heating under stirring and subsequent calcination. The results obtained by X-Ray diffractometry (XRD) showed diffraction patterns compatible with the standard obtained by ICSD-31152 and ICSD-61169 and they confirmed the formation of the lead titanate structure with and without gadolinium doping. The particle size of the samples obtained was calculated using XRD data and showed sizes compatible with those found in the literature.