Uso da técnica do pulso eletroacústico para o estudo de polietilenos e titanato zirconato de chumbo (PZT). / Use of the pulsed electroacoustic technique for the study polyethilens and lead zirconate titanate (PZT).

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The purpose this work was using to PEA method for investigation of the ferroelectrics response in PZT and space charge formation in polymeric materials (PE, XLPE) used as electrical insulation for high voltage devices. The PEA method is based on propagation acoustic signal generated by the application of a short electric field pulse, typically 5 ns in duration. Show all the steps of the experimental set-up PEA system, analysis of the electrical system and the mathematical treatment of the signals. Start up the work with double layer PET samples previously poled in corona triode with aim of determination of the origin of the signal obtained to in the sample-lower electrode interface and the experimental results obtained to PEA satisfactorily explain the theory. Make up his mind to apply a same idea to PZT, but only one sample it was poling. From that measurements with PET and PZT, is found that the signal come from of material biggest acoustic impedance. With the PEA method, in the first place development for polymers, it was investigated the ferroelectrics ceramics: ferroelectric switching, decaying of ferroelectric polarization after removal saturation electrical field, hysteresis loop measurements and the determination of coercive field. To obtain the electrical field profile through the thickness of the ferroelectrics ceramics it was applied ramp voltage method in process steady-state (low rate). The space charge formation in polymers under high electric field and in time function was investigated.

ASSUNTO(S)

pulsed electroacoustic xlpe space charge carga espacial xlpe pulso eletroacústico

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