All Ceramic Ion Sensor Using Dielectric BaTiO₃ Transducer

An all‐solid‐state impedance metric hydrogen‐phosphate ion sensor device has been tried to fabricate using BaTiO₃ as a transducer and spinel‐type oxide receptor. AC impedance measurement was carried out using flow‐cell system with boric‐acid buffer solution with hydrogen‐phosphate ion The Co₂RhO₄/BaTiO₃ sensor device was found to show impedance responses to hydrogen‐phosphate ion at 5 × 10⁻⁴ M and 1.0 × 10⁻² M with the 90% response time of ca. 150 s. The Co₂RhO₄/BaTiO₃ device showed good response characteristics among the tested devices in terms of sensitivity and restoration rate. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.