Functional conductive coatings for compensating near- electrode electrochemical processes in polar-cut α-LiIO₃ crystal samples

This study examined the temperature dependences of short-circuit currents in polar-cut α-LiIO₃ crystal samples with different combinations of of indium, silver, aluminum, and chromium conductive coatings. The coatings were applied to the opposite faces of the samples according to the sign of the piezoelectric response, which indicated the polarity of each face. Short-circuit currents were measured using the SKIP test system over the temperature range of 20–210 °C without an applied external electric field. Short-circuit currents were detected even at room temperature in the absence of prior external stimulation and could change by several orders of magnitude during heating. Both the magnitude and direction of the currents depended on the coating materials and on the polarity of the coated faces. For α-LiIO₃, the short-circuit currents were reduced to near-zero levels using two asymmetric coating configurations: Al(−)/In(+), with aluminum applied to the face exhibiting a negative piezoelectric response and indium to the face exhibiting a positive response; and Cr(−)/Al(+), with chromium applied to the negative-response face and aluminum to the positive-response face. The short-circuit currents remained within 10^–14–10^–13 A range were nearly temperature-independent up to 210 °C. These low current values indicate limited near-electrode electrochemical activity.

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