Hot isostatic press sintering and dielectric properties of SrTaO2N ceramics

SrTaO2N prepared by a citrate route was capsule hot isostatic press sintered at 196 MPa for 3 h at 1200, 1400 and 1600 degrees C. Densification over 80% was attained for all the sintered bodies with partial reduction, which was observed as a change of color from brown to dark gray. Exaggerated grain growth was observed with some amount of open pore for the product sintered at 1400 degrees C. The sample was successfully returned to the brown insulator color after annealing in ammonia flow at 1000 degrees C. The resultant SrTaO2N ceramics exhibited a considerably high relative dielectric permittivity of 7.8 x 10(3) at 10(2) Hz. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.