Complex capacitance in the representation of modulus of the lithium niobate crystals

Abstract

The lithium niobate (LiNbO 3 or LN) single crystal is grown in-house. The ac small-signal electrical characterization is conducted over a temperature range 35 ≤T≤150 °C as a function of measurement frequency (10 ≤f≤10 6 Hz). Meaningful observation is noted only in a narrow temperature range 59 ≤T≤73 °C. These electrical data when analyzed via complex plane formalisms revealed single semicircular relaxation both in the complex capacitance ( C ⁎) and in the modulus ( M ⁎) planes. The physical meaning of this kind of observation is obtained on identifying the relaxation type, and then incorporating respective equivalent circuit model. The simplistic non-blocking nature of the equivalent circuit model obtained via M ⁎-plane is established as the lumped relaxation is identified in the C ⁎-plane. The feature of the eventual equivalent circuit model allows non-blocking aspect for the LN crystal attributing to the presence of the operative dc conduction process. Identification of this leakage dc conduction via C ⁎-plane is portrayed in the M ⁎-plane where the blocking nature is removed. The interacting interpretation between these two complex planes is successfully presented.