Diffuse phase transition in Sr5RTi3Nb7O30 (R=La, Nd and Sm) Original Research Article

Polycrystalline samples of Sr5RTi3Nb7O30, (R=La, Nd and Sm) compounds were prepared by a high-temperature solid-state reaction technique. The formation and structure of the compounds were checked by preliminary X-ray studies. Detailed dielectric and electrical properties of the compounds as a function of frequency (1–100 kHz) and temperature (150–650 K) were studied. The temperature dependence of dielectric constant suggests that the compounds undergo ferro–paraelectric phase transition of diffuse type. Measurements of conductivity as a function of temperature suggest that the compounds have negative temperature coefficient of conductivity above 373 K.