Optimization of Ferroelectric Ceramics by Design at the Microstructure Level

Journal Article · Fri May 21 00:00:00 EDT 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3452071· OSTI ID:21361950

Jayachandran, K P; Guedes, J M; Rodrigues, H C ^[1]

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1. IDMEC-IST, Technical University of Lisbon, Mechanical Engineering, Av. Rovisco Pais, 1049-001 Lisbon (Portugal)

Ferroelectric materials show remarkable physical behaviors that make them essential for many devices and have been extensively studied for their applications of nonvolatile random access memory (NvRAM) and high-speed random access memories. Although ferroelectric ceramics (polycrystals) present ease in manufacture and in compositional modifications and represent the widest application area of materials, computational and theoretical studies are sparse owing to many reasons including the large number of constituent atoms. Macroscopic properties of ferroelectric polycrystals are dominated by the inhomogeneities at the crystallographic domain/grain level. Orientation of grains/domains is critical to the electromechanical response of the single crystalline and polycrystalline materials. Polycrystalline materials have the potential of exhibiting better performance at a macroscopic scale by design of the domain/grain configuration at the domain-size scale. This suggests that piezoelectric properties can be optimized by a proper choice of the parameters which control the distribution of grain orientations. Nevertheless, this choice is complicated and it is impossible to analyze all possible combinations of the distribution parameters or the angles themselves. Hence we have implemented the stochastic optimization technique of simulated annealing combined with the homogenization for the optimization problem. The mathematical homogenization theory of a piezoelectric medium is implemented in the finite element method (FEM) by solving the coupled equilibrium electrical and mechanical fields. This implementation enables the study of the dependence of the macroscopic electromechanical properties of a typical crystalline and polycrystalline ferroelectric ceramic on the grain orientation.

• OSTI ID: 21361950
• Journal Information: AIP Conference Proceedings, Vol. 1233, Issue 1; Conference: 2. international symposium on computational mechanics; 12. international conference on the enhancement and promotion of computational methods in engineering and science, Hong Kong (Hong Kong); Hong Kong (Hong Kong), 30 Nov - 3 Dec 2009; 30 Nov - 3 Dec 2009; Other Information: DOI: 10.1063/1.3452071; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CERAMICS
CRYSTALLOGRAPHY
EQUILIBRIUM
FERROELECTRIC MATERIALS
FINITE ELEMENT METHOD
GRAIN ORIENTATION
MONOCRYSTALS
OPTIMIZATION
PIEZOELECTRICITY
POLYCRYSTALS
RANDOMNESS
SIMULATION
STOCHASTIC PROCESSES
CALCULATION METHODS
CRYSTALS
DIELECTRIC MATERIALS
ELECTRICITY
HEAT TREATMENTS
MATERIALS
MATHEMATICAL SOLUTIONS
MICROSTRUCTURE
NUMERICAL SOLUTION
ORIENTATION