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In the present study, particular aspects of the large-signal switching properties and electromechanical hysteresis of the lead zirconate titanate (PZT)-type porous piezoceramics were studied in comparison with the dense piezoceramics of the same composition. Large-signal ferroelectric polarization and strain hysteresis loops were recorded at the bipolar electric fields in the range of 0 ÷ 5 kV/mm and in the frequency range of 0.01 ÷ 5 Hz. Measurements and analysis were performed by means of the electromechanical measurement system (STEPHV) and electromechanical response characterization program (STEP), combining large-signal modeling of the mechanical and electrical behavior of ferroelectric materials. [ABSTRACT FROM AUTHOR]

In this work, the piezoelectric hysteresis and relaxation process induced by a weak DC electric field in ferroelectric ceramics were studied using the impedance spectroscopy method and piezoelectric resonance analysis program (PRAP). The DC field and time dependences of the complex dielectric constants were measured for the radial extensional mode of vibrations of thin piezoceramic disks. It was found that the hysteresis and relaxation nature of the field and time dependences of the complex dielectric constants were caused by the reversible displacements of 90° domain walls as well as the space charge transformation. [ABSTRACT FROM AUTHOR]

In this work, a new method for study of the process of domain orientations and space charge relaxation in ferroelectrics using the surface acoustic waves (SAW) has been developed. The results of an experimental study of the dc electric field influence on the parameters of SAW propagation in piezoceramics with different ferroelectric "hardness" are presented. [ABSTRACT FROM AUTHOR]

In this work, we studied the piezoelectric hysteresis effect induced by a weak dc electric field in ferroelectric ceramics. Precision measurements of the impedance spectra for the thickness vibrational mode of thin piezoceramic disks at different polarities of applied dc electric field were performed using the method and program of piezoelectric resonance analysis (PRAP). The field dependences of the complex piezoelectric constants of piezoelectric ceramics obtained by processing successively measured impedance spectra were analyzed and a physical interpretation of the results was proposed. [ABSTRACT FROM AUTHOR]

A new method for studying nonlinear processes in ferroelectric ceramics under the action of external factors is proposed, which is based on the measurement and analysis of piezoelectric resonance spectra. The proposed method provides high-accuracy determination of complex parameters, including the elastic, dielectric, and piezoelectric constants of studied ferroelectric materials, and their changes caused by external factors. The nonlinear processes were studied by measuring the complex electromechanical parameters of "soft" ferroelectric ceramics based on lead zirconate titanate (PZT) as functions of the applied constant electric field. A physical interpretation of the obtained results is suggested. [ABSTRACT FROM AUTHOR]

The article presents a new method of electromechanical characterization of ferroelectric materials. The measurements of the complex elastic, electromechanical, and piezoelectric parameters of ferroelectric ceramics were fulfilled using the piezoelectric resonance analysis method. To study nonlinear processes occurring in ferroelectric ceramics under the external influences the dc electric field, dependencies of the complex electromechanical parameters of the PZT type piezoceramics were measured and analyzed. [ABSTRACT FROM AUTHOR]

In this paper, the study of relaxation processes in ferroelectric ceramics under the influence of a dc electric field has been performed. To measure the field and time dependences of the complex elastic, dielectric, and piezoelectric parameters of ferroelectric ceramics, the impedance spectroscopy method and piezoelectric resonance analysis program were used. A comparative analysis of various characterization methods was carried out, and a physical interpretation of the results has been proposed. [ABSTRACT FROM AUTHOR]

Abstract—A new method is proposed for studying relaxation and transient processes in ferroelectric ceramics under the influence of a constant electric field. Precision measurements of the time dependences of the complex permittivity of ferroelectric ceramics in the region of weak electric fields were carried out using the method of impedance spectroscopy. A comparative analysis of various methods for characterizing relaxation processes in ferroelectric ceramics has been carried out. A physical interpretation of the results is proposed. [ABSTRACT FROM AUTHOR]