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

The lithium niobate (LiNbO3 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≤106 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.