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Piezoelectric multilayer composite thin films based on Pb(Mg1/3Nb2/3)O3?PbTiO3: preparation and characterization
| Content Provider | Semantic Scholar |
|---|---|
| Author | Hosiny, Haitham El Mohammed, Ali |
| Copyright Year | 2013 |
| Abstract | vii ABSTRACT The ferroelectric composition (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMNT), close to the morphotropic phase boundary (MPB) at x=0.35, has excellent piezoelectric coefficients in single-crystals and bulk ceramics. The progressive miniaturization of the devices leads to the preparation of PMNT in thin film form for their integration in microelectronic devices. However, in thin film form, it has been reported that the remnant properties of PMNT are reduced as compared to those of the corresponding bulk materials, which has been attributed to grain size effects. Nevertheless, in the ferroelectric loops the polarization saturation values remain close to those obtained in bulk ceramics, which implies that the problem relies on the decrease of the remnant polarization values in the thin films. In this doctoral thesis the principles traditionally used in bulk composites are followed. The combination of layers with different ferroelectric compositions in a multilayer composite (MLC) configuration has proved to be successful to improve the dielectric and ferroelectric (remnant) properties when compared to those of the individual layers. Based on this idea, this thesis explores the preparation and characterization of piezoelectric multilayer composite films based on Pb(Mg1/3Nb2/3)O3–PbTiO3, with the objective of finding a solution to the limitations found in thin film form with the remnant piezoelectric coefficients. The chemical solution deposition (CSD) method was used in this PhD thesis for the fabrication of the films on platinised silicon-based substrates. The XRD patterns and the study of the evolution of the dielectric permittivity with the temperature of the MLC films indicate that there is no significant interdiffusion between the alternating PT and PMNT layers, which confirms that CSD is an excellent method to prepare these multilayer composite films. The hypothesis is that the remnant piezoelectric can be improve if the polarization on the PMNT layers is kept by an internal electric field produced from the neighbouring poled PbTiO3 (PT) in MLC films with 2-2 connectivity configuration. The normal ferroelectric PT has large remnant polarization values. In this thesis we firstly study multilayer composite films with very thin alternating layers for which the application of an electric field should be highly effective, both due to the small thickness of the layers, and to the enhanced interactionThe ferroelectric composition (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMNT), close to the morphotropic phase boundary (MPB) at x=0.35, has excellent piezoelectric coefficients in single-crystals and bulk ceramics. The progressive miniaturization of the devices leads to the preparation of PMNT in thin film form for their integration in microelectronic devices. However, in thin film form, it has been reported that the remnant properties of PMNT are reduced as compared to those of the corresponding bulk materials, which has been attributed to grain size effects. Nevertheless, in the ferroelectric loops the polarization saturation values remain close to those obtained in bulk ceramics, which implies that the problem relies on the decrease of the remnant polarization values in the thin films. In this doctoral thesis the principles traditionally used in bulk composites are followed. The combination of layers with different ferroelectric compositions in a multilayer composite (MLC) configuration has proved to be successful to improve the dielectric and ferroelectric (remnant) properties when compared to those of the individual layers. Based on this idea, this thesis explores the preparation and characterization of piezoelectric multilayer composite films based on Pb(Mg1/3Nb2/3)O3–PbTiO3, with the objective of finding a solution to the limitations found in thin film form with the remnant piezoelectric coefficients. The chemical solution deposition (CSD) method was used in this PhD thesis for the fabrication of the films on platinised silicon-based substrates. The XRD patterns and the study of the evolution of the dielectric permittivity with the temperature of the MLC films indicate that there is no significant interdiffusion between the alternating PT and PMNT layers, which confirms that CSD is an excellent method to prepare these multilayer composite films. The hypothesis is that the remnant piezoelectric can be improve if the polarization on the PMNT layers is kept by an internal electric field produced from the neighbouring poled PbTiO3 (PT) in MLC films with 2-2 connectivity configuration. The normal ferroelectric PT has large remnant polarization values. In this thesis we firstly study multilayer composite films with very thin alternating layers for which the application of an electric field should be highly effective, both due to the small thickness of the layers, and to the enhanced interaction |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://digital.csic.es/bitstream/10261/76895/1/PhD%20thesis%20H%20el%20Hosiny%202013.pdf |
| Alternate Webpage(s) | https://repositorio.uam.es/bitstream/handle/10486/13743/64535_haitham%20el%20hosiny%20ali%20mohammed.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
