Structural, thermal and dielectric properties of barium lanthanum niobate:A potential material for substrate application

Barium lanthanum niobate has been prepared as single phase compound by soli d-state route. The structure of Ba2LaNbO6 has been studied by power X-ray d iffraction method and was found to have a cubic perovskite (A(2)BB'O-6) str ucture with a lattice constant a=8.60 Angstrom. Ba2LaNbO6 did not show any phase transition in the temperature range 30-1300 degreesC as revealed by D TA studies. Thermal expansion coefficient of Ba2LaNbO6 measured by TMA stud ies was 8.1 x 10(-6)degreesC(-1). The specific heat capacity of Ba2LaNbO6 o btained from DSC measurements was 383 Jkg(-1)K(-1) and the thermal diffusiv ity measured following the photoacoustic technique was found to be equal to 0.25cm(2)s(-1). Ba2LaNbO6 has a moderately low dielectric constant and los s factor values making it suitable as substrate for microwave applications. (C) 2001 Kluwer Academic Publishers.