Nanostructured MgTiO3 thick films obtained by electrophoretic deposition from nanopowders prepared by solar PVD

Abstract

A novel combination of solar physical vapor deposition (SPVD) and electrophoretic deposition (EPD) that was developed to grow MgTiO3 nanostructured thick films is presented. Obtaining nanostructured MgTiO3 thick films, which can replace bulk ceramic components, a major trend in electronic industry, is the main objective of this work. The advantage of SPVD is direct synthesis of nanopowders, while EPD is simple, fast and inexpensive technique for preparing thick films. SPVD technique was developed at CNRS-PROMES Laboratory, Odeillo-Font Romeu, France, while the EPD was performed at University of Aveiro DeMAC/CICECO, Portugal. The nanopowders with an average crystallite size of about 30 nm prepared by SPVD were dispersed in 50 ml of acetone in basic media with addition of triethanolamine. The obtained well dispersed and stable suspensions were used for carrying out EPD on 25 mu m thick platinum foils. After deposition, films with thickness of about 22-25 mu m were sintered in air for 15 min at 800, 900 and 1000 degrees C. The structural and microstructural characterization of the sintered thick films was carried out using XRD and SEM, respectively. The thickness of the sintered samples were about 18-20 mu m, which was determined by cross-sectional SEM. Films sintered at 900 degrees C exhibit a dielectric constant, epsilon(r) similar to 18.3 and dielectric loss, tan delta similar to 0.0012 at 1 MHz. The effects of processing techniques (SPVD and EPD) on the structure, microstructure and dielectric properties are reported in detail. The obtained results indicate that the thick films obtained in the present study can be promising for low loss materials for microwave and millimeter wave applications. (C) 2015 Published by Elsevier B.V.