Ceramics-Silikáty 49 (1) 29-33 (2005)

Synthesis, structure and conductivity of layered perovskites

N. Velinov, N. Brashkova, V. Kozhukharov

By using the nitrate-citrate method we have been able to synthesize layered perovskites from the Ruddlesden-Popper (R-P) phases (LaSr)_n+1FenO3_n+1, where n = 1, 2, 3. In this paper we present the results about their thermal evolution during the wet-chemical synthesis, structural and microstructural characterization by means of thermogravimetry/ differential thermal analysis, X-ray diffraction and scanning electron microscopy. By measuring the total conductivity, using 4-probe DC method an attempt to correlate structure and conductivity of layered perovskites has been made. We established that at temperature over 140°C electrical conductivity of triple layer LaSr₃Fe₃O₁₀ perovskite is significantly higher compared with these of single and double layer compounds. The materials possess potentially applicable mixed electron-ion conductivity and catalytic activity, as well.

Keywords: Layered perovskites, Ruddlesden-Popper phase, Conductivity