Microstructural variation and dielectric properties of KTiNbO5 and K3Ti5NbO14 ceramics

Abstract

KTiNbO5 (KTN) and K3Ti5NbO14 (3K5TN) ceramics sintered at 1150 degrees C and 1125 degrees C, respectively, exhibited a dense, homogeneous microstructure with a high relative density (>= 96% of the theoretical density). Abnormal grain growth occurred in both specimens during sintering, and large (002) and (001) grains developed in KTN and 3K5TN ceramics, respectively. A dielectric constant (epsilon(r)) of 13 and a dielectric loss of 2.9% at 10 MHz were obtained from KTN ceramics sintered at 1150 degrees C. The 3K5TN ceramics sintered at 1125 degrees C showed an epsilon(r) of 15 and a dielectric loss of 12% at 10 MHz. The resistivity of KTN and 3K5TN ceramics was low and their epsilon(r) and dielectric loss values displayed lowfrequency dispersion (LFD); the presence of K+ ions between the layers could be responsible for their low resistivity and LFD. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.