Microstructural and electrical properties of PbTIO3 screen-printed thick films

In this article we will study the structural and electrical properties of PbTiO3 (PTO) screen-printed thick films. These properties can change with synthetic routes employed for synthesis of PTO. The ceramic powder has been synthesized by mechanical alloying and solid state route. This material crystallizes in the tetragonal system, with space group P4mm and unit cell dimensions a = b = 3.904, c = 4.152 angstrom, and Z = 1. From our results, it was observed that PTO obtained by mechanical alloying provides smaller crystallite size. The Rietveld refinement showed that the samples synthesized by mechanical alloying and solid state route crystallize in the tetragonal system but with different cell parameters. The Raman shifts of these films agree with modes from literature. However, some displacements happen, because the morphology and structural characteristics of the thick films are different, compared to single crystal and thin film. The photomicrographs of the PTO thick films showed that the choice of synthetic routes obtained samples with different microstructures.191097398

Microstructure and magneto-dielectric properties of ferrimagnetic composite GdIG(X):YIG(1-X) at radio and microwave frequencies

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The gadolinium iron garnet (GdIG, Gd3Fe5O12) and yttrium iron garnet (YIG, Y3Fe5O12), and their GdIG(X):YIG(1-X) composites, were obtained by a new solid-state procedure. The microstructure of the samples was studied by X-ray powder diffraction and Rietveld refinement, Vickers microhardness and scanning electron microscopy. The density and microhardness behavior were studied as a function of the lattice parameters for the composite samples. In the present work, the magnetic and dielectric properties of the GdlG(X):YIG(1-X) composite at radio and microwave frequencies were also studied. The magnetic permeability and dielectric permittivity and loss properties for the composite GdIG(X):YIG(1-X) showed good potential for use in components, when one is looking for moderate epsilon(r)' and mu(r)' materials with low loss in the radio-frequency and microwave range. (C) 2009 Elsevier Ltd. All rights reserved.705804810Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FUNCAP (Brazilian agencies)CELESTICAUS Air Force Office of Scientific Research (AFOSR) [FA9550-08-1-0210]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)US Air Force Office of Scientific Research (AFOSR) [FA9550-08-1-0210