Skip to Main content Skip to Navigation
Theses

Síntese, caracterizaçãi elétrica e estructural de cerâicas ferroelétricas de composição Ba0,90R0,10Ti1-xZrxO3 (R=Ca, Sr)

Abstract : The aims of this work is to study the structural and electrical properties of ceramic samples belonging to the Ba1-xRxTi1-yZryO3 (R = Ca, Sr) system. The powder samples presenting a micro or nanosize were respectively obtained by using a mixture of oxides and by the modified polymeric precursor methods. From the samples in a powder form, micro or nanosize, sintered ceramic samples were obtained through a sintering process at high temperature. Micrometer scale ceramic samples were obtained through the traditional method of sintering at high temperature while nano-sized particles ceramics were obtained using the spark Spark Plasma Sintering SPS technique. The structural and electrical properties of these two sets of samples were characterized using High resolution X-ray diffraction (XRD), complex impedance spectroscopy and X-ray absorption and Raman spectroscopy's. Through the data of XRD it was possible to follow the processes of phase transition due to the substitution of Ti by Zr atoms. Electrical measurements showed that as the amount of Zr increases, the sample passes from a normal ferroelectric state to a relaxor state. Measurements of the absorption and Raman spectra were used to establish a relationship between local structure and electrical properties displayed by these materials. These properties were characterized by the shape of the dielectric permittivity curves versus temperatures. Two principal characteristics were analysed : the maximum Tm and the width ∆T. Finally, the analysis of results obtained with nanostructured ceramic samples showed that reducing the particle size leads to a decrease of Tm, and a small increase of ∆T. However, there was no change from normal to relaxor ferroelectric states
Complete list of metadatas

Cited literature [64 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00596848
Contributor : Abes Star :  Contact
Submitted on : Monday, May 30, 2011 - 1:18:07 PM
Last modification on : Wednesday, December 4, 2019 - 4:39:20 PM
Long-term archiving on: : Wednesday, August 31, 2011 - 2:27:43 AM

File

TH2010PEST1061_complete.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00596848, version 1

Collections

Citation

Higor Favarim. Síntese, caracterizaçãi elétrica e estructural de cerâicas ferroelétricas de composição Ba0,90R0,10Ti1-xZrxO3 (R=Ca, Sr). Other [cond-mat.other]. Université Paris-Est, 2010. Portuguese. ⟨NNT : 2010PEST1061⟩. ⟨tel-00596848⟩

Share

Metrics

Record views

394

Files downloads

905