The aim of this study is to produce Nb doped PZT thin films and then investigate the
effects of Nb+5 ion on the structural, dielectric and ferroelectric properties. Niobium
(Nb) doped lead zirconate titanate thin films (PNZT) were produced by solution
deposition with nominal compositions, Pb(1-0.5x)(Zr0.53Ti0.47)1-xNbxO3 where x = 0.00 -
0.07. Single and multi-layered films were deposited onto (111)-Pt/Ti/SiO2/Si-(100)
substrates by spin coating. PZT compositions near the morphotropic phase boundary
(MPB) was chosen because excellent ferroelectric and dielectric properties were
achieved in this area.
The effects of sintering temperature, sintering time, variation of thickness in the
films and change of niobium content were investigated with regard to phase
development, microstructure, and ferroelectric and dielectric characteristics. The best
results were obtained in double layered films (390 nm) which were sintered at 600
° / C for 1 h. Grain size of the films decreases with increasing Nb content except for 1
at % Nb doped films. The average grain size of 1 at % Nb doped thin films was
calculated as 130 nm by using FESEM.
Optimum doping level was found in 1 at % Nb doped films. For 1 at % Nb doped
[Pb0.995(Zr0.53Ti0.47)0.99Nb0.01O3] films, remnant polarization (Pr) of 35.75 & / #956 / C/cm2 and
coercive field (Ec) of 75.65 kV/cm have been obtained. The maximum dielectric
constant was achieved in 1 at % Nb doped films which was 689. Tangent loss values
were found between 2-4 % and these values were independent of Nb concentrations.
Ferroelectric and dielectric properties were decreased at higher Nb doping levels
because of the changes in the grain size, distortion of the crystal structure and
pinning of the domains.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12609350/index.pdf |
| Date | 01 February 2008 |
| Creators | Kayasu, Volkan |
| Contributors | Ozenbas, Macit |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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