Investigation of the Piezoelectric Resonance in Stoichiometric LiNbO3 Crystals at High Temperatures and Conductivities

Resumo

The piezoelectric characteristics, dielectric properties, and ionic conductivity of close-to-stoichiometry LiNbO\(_{{{{3}_{{{\text{stoich}}}}}}}\) crystals have been investigated in a wide temperature range (300–850 K) with the aim of establishing the conditions of use of lithium-niobate-based piezoelectric resonators at high temperatures and, accordingly, high conductivities. It is shown that the piezoelectric phenomenon in LiNbO\(_{{{{3}_{{{\text{stoich}}}}}}}\) crystals is observed in a certain temperature range ΔT (and, correspondingly, at certain static-conductivity relaxation times Δτ_V) and a frequency range Δω_R at the condition \(\tau _{V}^{{ - 1}}\)\( \ll \) ω_R satisfied. Apparently, not only LiNbO\(_{{{{3}_{{{\text{stoich}}}}}}}\) crystals exhibit such regularities, but also some other piezoelectric materials.