Enhancement of the pyroelectric coefficient of lithium niobate crystals

Abstract

This work achieved a significant enhancement of the pyroelectric coefficient of congruent lithium niobate (CLN) crystals through reduction treatment. The pyroelectric coefficient increased from 1.08 × 10−4 to 3.42 × 10−4 C/m2 K, with a 3.17-fold enhancement. The analysis of the Raman scattering spectra and infrared absorption spectra shows that reduction treatment causes oxygen atom loss in the LN crystal lattice, and the defect structure caused by oxygen atom loss changes the behavior of lattice-vibrational mode A1-1. Appropriate reduction treatment can increase the asymmetry factor of the A1-1 mode in CLN crystals, thereby enhancing the pyroelectric coefficient. A nearly linear relationship exists between the asymmetry factor and the pyroelectric coefficient.