A bibliography is given containing 2067 references published during 2002 and 2003 on piezoelectric and pyroelectric properties of materials and their applications. It contains listings of journal articles with complete bibliographic citations. This bibliography is the continuation of a series published semi-annually.

Guide to the Literature of Piezoelectricity and Pyroelectricity. 23

Fabrication of Fe–Cu matrix diamond composite by microwave hot pressing sintering

The electric transient response method is an effective technique to evaluate material constants of piezoelectric ceramics under high-power driving. In this study, we tried to incorporate nonlinear piezoelectric behaviors in the analysis of transient responses. As a base for handling the nonlinear piezoelectric responses, we proposed an assumption that the electric displacement is proportional to the strain without phase lag, which could be described by a real and constant piezoelectric e-coefficient. Piezoelectric constitutive equations including nonlinear responses were proposed to calculate transient responses of a piezoelectric resonator. The envelopes and waveforms of current and vibration velocity in transient responses observed in some piezoelectric ceramics could be fitted with the calculation including nonlinear responses. The procedure for calculation of mechanical quality factor Qm for piezoelectric resonators with nonlinear behaviors was also proposed.

Analysis of nonlinear transient responses of piezoelectric resonators

We report high-quality and high-density B1 3.25 La 0.75 Ti 3 O 12 ceramics prepared by sintering at a low temperature of 900°C from the nanosized powder with a diameter around 100 nm synthesized by the flash creation method. The densification at 900°C, which was 300°C lower sintering temperature compared with conventional solid-state reaction, enables us to obtain the ceramics showing a remanent polarization of 14.5 μC/cm 2 , a coercive field of 50 kV/cm and a leakage current of ∼10 -9 A/cm 2 . The superior properties are indicated to originate from lower defect concentration achieved by the low temperature sintering.

Flash Creation Method 生成ナノ粉末を用いて作製した高品質非鉛強誘電体セラミックス

In this paper, a comprehensive methodology for characterizing the high power resonance behavior of bulk piezoelectric ceramics using the burst method is described. In the burst method, the sample is electrically driven at its resonance frequency, and then either a short circuit or an open circuit condition is imposed, after which the vibration decays at the resonance or antiresonance frequency, respectively. This decay can be used to measure the quality factor in either of these conditions. The resulting current in the short circuit vibration condition is related to the vibration velocity through the “force factor.” The generated voltage in the open circuit vibration condition corresponds to the displacement by the “voltage factor.” The force factor and the voltage factor are related to material properties and physical dimensions of the sample. Using this method, the high power behavior of the permittivity, compliance, effective piezoelectric charge constant, electromechanical coupling factor, and material losses can be determined directly by measuring the resonance (short circuit) and antiresonance (open circuit) frequencies, their corresponding quality factors, the force factor A, and the voltage factor B. The experimental procedure to apply this method is described and demonstrated on commercially available hard and semi-hard PZT materials of k31 geometry.

Characterization of Piezoelectric Ceramics Using the Burst/Transient Method with Resonance and Antiresonance Analysis

Fundamental and 3rd-harmonic voltages between a pair of electrodes, appearing due to nonlinearity, were theoretically calculated in a piezoelectric rectangular vibrator which was driven by a sinusoidal constant current having the resonance frequency of length-extensional 1/2λ-mode vibration. The theoretical calculation was performed using the electrical equivalent circuit of a piezoelectric rectangular vibrator. Since the fundamental and 3rd-harmonic voltages were generated with cosine distributions in the sample and the motional impedance to each generated voltage also has a cosine distribution, Millman's theorem was used in the analysis of the fundamental and 3rd-harmonic voltages between a pair of electrodes. This analysis clarifies quantitatively the relationship between the nonlinear voltages between electrodes and a nonlinear coefficient used as a material constant.

Measurement of the Nonlinear Coefficient of a Third-Higher Term in Lead Zirconate Titanate Piezoelectric Ceramics

An effective 3rd nonlinear piezoelectric coefficient for a vibrator in a piezoelectric ceramic with a rectangular shape was measured using a constant-current circuit. On the base of the nonlinear piezoelectric equation, we applied three different measurement methods: (1) the change of the resonance frequency with increasing sample current; (2) the change of magnitude of nonlinear fundamental voltage; (3) the change of magnitude of the 3rd harmonic voltage. The methods were evaluated and compared with respect to their simplicity and accuracy.

Comparison among three measurement methods of the nonlinear piezoelectric coefficient of a third-higher term in lead zirconate titanate piezoelectric ceramics

It has been shown in our previous work that the 28 GHz microwave sintering process can improve the performances of piezoelectric actuators. The improved performances include larger output force, higher strength and a larger electromechanical coupling factor. The improvement in performances is attributed to the repression of grain growth due to rapid heating and improvement of the microstructure because of internal heating. The sintering time was reduced to 1/10 the time needed for the conventional technology due to the larger power and uniform heating in the microwave sintering process. In this study, the microwave sintering process was combined with the hot-press sintering process for further improvement of the performances of lead zirconate titanate (PZT) actuators and the sintering conditions of the hybrid process were investigated. It was confirmed that the combination of microwave and hot-press sintering processes can improve the performances of sintered PZT. In particular, it was found that the piezoelectric constant d31 could be improved by as much as 30%.

Fabrication of High-Performance Lead Zirconate Titanate Actuators Using the Microwave and Hot-Press Hybrid Sintering Processes

Piezoelectric materials play an important role in smart material and structural systems, and high-performance piezoelectric actuators with larger force and displacement output are in demand It was shown in our previous work that the hybrid sintering process using a 28 GHz microwave technique and hot pressing offers advantages over conventional technologies reference It was also confirmed that the maximum achieved value of piezoelectric constant d31 of the specimens of the hybrid-sintering process is approximately 360×10-12 m/V, which is about 38% larger than 260×10-12 m/V, the d31 of the conventionally sintered specimens In this study, the material properties, including electromechanical coupling factor, Young's modulus, frequency constant, Curie temperature and dielectric constant, of the specimens fabricated with the microwave sintering process were further investigated for different sintering temperatures The Curie point Tc decreases, but the dielectric constant er at Tc increases with the grain size of specimens for all sintering methods The influence of grain size on Tc and er can be attributed to the residual stress induced by the lattice mismatch between the cubic phase and the tetragonal-rhombohedral mixed phase

Properties of Lead Zirconate Titanate Ceramics Determined Using Microwave and Hot-Press Hybrid Sintering Process.

In order to experimentally demonstrate our theory concerning a nonlinear piezoelectric coefficient, a nonlinear piezoelectric coefficient of the 3rd higher term, ξD31, which is a material constant, was measured in rectangular piezoelectric ceramics different in size and electrode configuration. The value of ξD31 was obtained through our theoretical calculation which deduces the relationship between the nonlinear coefficient as a material constant (ξD31) and the effective nonlinear coefficient (ξD31') for each vibrator. The conversion coefficient from ξD31' to ξD31 was calculated by considering the distribution of electric flex density on the electrode in each sample.

https://iopscience.iop.org/article/10.1143/JJAP.41.7095/pdf

Kunihiro Nagata

Papers

Measurement of the Nonlinear Coefficient of a Third-Higher Term in Lead Zirconate Titanate Piezoelectric Ceramics

Comparison among three measurement methods of the nonlinear piezoelectric coefficient of a third-higher term in lead zirconate titanate piezoelectric ceramics

Fabrication of High-Performance Lead Zirconate Titanate Actuators Using the Microwave and Hot-Press Hybrid Sintering Processes

Properties of Lead Zirconate Titanate Ceramics Determined Using Microwave and Hot-Press Hybrid Sintering Process.

Relation between Sample Configurations and Nonlinear Piezoelectric Coefficients