A method is proposed to measure shock-induced electrical conductivity in electrically active dielectrics -piezoelectrics and ferroelectrics. Results of measurements of electrical conductivity in single-crystal quartz are reported.An analysis of the literature [1] shows that the overwhelming majority of experimental data on the shockinduced electrical conductivity of materials were obtained by electrocontact methods of measuring electrical resistance. All of them are based on the application of an electrical voltage to the material sample studied or on the passage of an electric current from an external source through the sample [1]. These methods, however, are unsuitable for measuring shock-induced electrical conductivity (SIEC) in piezoelectrics and ferroelectrics because shock-wave (SW) action generates an electric field of strength up to 10 7 -10 8 V/m [2] in these materials due to the piezoeffect or shock depolarization, and the effect in question can hardly be identified against the background of the generated fields.SIEC is an important characteristic in the use of piezoelectrics and ferroelectrics as a working medium of dynamic pressure transducers [2] and explosive piezogenerators [3]. However, because of the lack of experimental data on SIEC, this quantity was not taken into account quantitatively in phenomenological and computational models for the electrical response of the abovementioned devices to SW action [2,4,5]. There has been an attempt to measure SIEC in piezoceramics using the voltmeter-ammeter method and the oscillating circuit method [6]. Generally, however, measurements can be performed on unpolarized material samples or the time when depolarization processes in a material have been completed. Therefore, they have a limited range region of application.In the present study, we propose a method for measuring SIEC in piezoelectrics and ferroelectrics which is based on the use of the electric field generated in the material under SW action. A similar approach was employed in [7] to develop a procedure for measuring radiation-induced electrical conductivity in pyroelectrics. SIEC MEASUREMENT METHODLet us derive a differential equation that describes the electrical response of a piezoelectric or ferroelectric sample to SW action taking into account shock-induced electrical conductivity. A schematic representation of the sample is given in Fig. 1.The sample in the shape of a rectangular parallelepiped with dimensions x 0 × y 0 × z 0 is placed in a dielectric medium. Thin metal electrodes are applied on its faces parallel to the plane Y Z. A load resistance R load is switched between the electrodes. A plane SW prorogates at a velocity D along the Z axis.The SW front divides the sample into a compressed and an uncompressed zones. Leakage of the generated electric charge can occur on the face of the sample parallel to the coordinate plane XY (the corresponding surface electrical conductivity is σ 1 ), on the faces par-96 0010-5082/07/4301-0096

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Abstract. Cerium has a complex phase diagram that is explained by the presence of structure phase transitions. Planar gauges were used in various combinations in experiments for determination of sound velocity dependence on pressure in cerium by the technique of PVDF gauge. The data of time dependence on pressure profiles with use of x(t) diagrams and the D(u) relation for cerium allowed the definition of the Lagrangian velocity of the unloading wave C Lagr and the Eulerian velocity C Eul by taking into account the compression σ . These results accords with data obtained by using the technique of VISAR and a manganinbased gauge, and calculated pressure dependence of isentropic sound velocity according to the VNIITF EOS. Metallography analysis of post-experimental samples did not find any changes in a phase composition.

This paper gives the results of measurement of shock-induced electrical conductivity in ferroelectrics: PKR-1 lead zirconate-titanate piezoceramic, deuterated triglycerine sulphate single crystal, and polymer polyvinylidene fluoride.