Phase Transitions of KIO3 Ferroelectrics in Al2O3-Based Nanoporous Matrices

Resumo

Temperature dependences of the linear permittivity ε' and the third harmonic amplitude γ_3ω of composites prepared by introducing ferroelectrics KIO₃ into matrices of porous aluminum oxide Al₂O₃ with pore sizes of 240 nm were studied. It is found that the IV → III and III → II structural transition temperatures of potassium iodide in Al₂O₃ pores decrease by 5 K and 24 K, respectively, with respect to bulk KIO₃. The measurements of the dielectric properties do not reveal V → IV and II → I phase transitions in the composite samples.