Thesis
Fabrication, materials, and characterization for efficient MEMS power generation
Washington State University
Master of Science (MS), Washington State University
2004
Handle:
https://hdl.handle.net/2376/229
Abstract
Changes to the fabrication of lead zirconate titanate have been made to improve the processing efficiency and decrease the environmental hazards in the production of a piezoelectric thin film-based MEMS engine. Several trials of non-2-MOE-based solution deposition routes were attempted, finding an acetate-based hybrid sol-gel route to provide films of good quality with decreased processing times. Additionally, the incorporation of rapid thermal annealing (RTA) for crystallization of the sol-gel films is shown to be a practical replacement to the conventional furnace currently used in the PZT processing scheme. Viability of this route was determined through characterization of the structure (FESEM, AFM and XRD) and properties (dielectric constant, transverse piezoelectric coefficients, electromechanical response, and film stress). Further improvements to the PZT thin film were investigated from studying the processing-structure-property relationship for various parameters, such as solution chemistry, dopant additions, and heat treatment. Three chemistries of sol-gel derived PZT were prepared, 32/68, 40/60, and 52/48. Increased piezoelectric response was obtained with 52/48 chemistry, showing a rhombohedral structure, which deviates from the tetragonal structures of the former two chemistries. From doping the 32/68 and 52/48 chemistries with various amount of donor dopant, niobium (0-7.8 mol% Nb), a strong change in the grain morphology from columnar to equiaxed was observed as dopant concentration increased. Correlating these structure changes with the measured properties show that columnar grains do not always lead to the best combination of properties. Rather, the highest piezoelectric coefficients and dielectric constants were observed for undoped and lightly doped Pb1.1(Zr0.52Ti0.48)1-xNbxO3 where x ≤1.1 mol% Nb. The PZT chemistries that produced the lowest stresses were undoped 40/60 and 2.8 mol% Nbdoped 32/68 and 52/48.
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Details
- Title
- Fabrication, materials, and characterization for efficient MEMS power generation
- Creators
- Julia Vivian Martinez
- Contributors
- David F. Bahr (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525080901842
- Language
- English
- Resource Type
- Thesis