The constant electric field effect on the radio absorption of crystals BaTiO3 and piezoceramics PCR-1

Abstract

The effect of a constant electric field (E) on the absorption of microwave electromagnetic energy (L) by BaTiO3 crystals and the highly sensitive PCR-1 piezoceramic was studied. The field dependence of the absorption value L(E) at the maximum of the spectrum L(f) has the form of a “butterfly”, and the dependence of the frequency shift of the maximum on the field strength f(E) has a hysteretic character. The PCR-1 L(f) absorption spectrum at high E is modulated by pulses in a wide frequency range. It is assumed that the cause of the amplitude–frequency modulation of the spectrum may be the electromagnetic radiation of incomplete local discharges at the surface of piezoceramics. The change in the magnitude and position of the resonance maximum in the absorption spectra and the appearance of amplitude–frequency modulation L(f) when exposed to a constant field is interpreted from the point of view of changes in the parameters and concentration of the domains walls, as well as the a- and c-domain wedges of mechanical twins resonating in the electromagnetic field.

Keywords

• microwave
• absorption
• spectrum
• piezoceramics
• dispersion
• domain walls
• micro breakdowns