Adjustable dielectric properties of Li2CuxZn1-xTi3O8 (x=0 to 1) ceramics with low sintering temperature

Single-phase dielectric ceramics Li2CuxZn1-xTi3O8 (x = 0-1) were synthesized by the conventional solid-state ceramic route. All the solid solutions adopted Li2MTi3O8 cubic spinel structure in which Li/M and Ti show 1:3 order in octahedral sites whereas Li and M are distributed randomly in tetrahedral sites with the degree of Li/M cation mixing varying from 0.5 to 0.3. The substitution of Cu for Zn effectively lowered the sintering temperatures of the ceramics from 1050 to 850 degrees C and significantly affected the dielectric properties. As x increased from 0 to 0.5, tau(f) gradually increased while the dielectric constant (epsilon(r)) and quality factor value (Q x f) gradually decreased, and a near-zero tau(f) of 1.6 ppm/degrees C with epsilon(r) of 25.2, Q x f of 32,100 GHz could be achieved for Li2Cu0.1Zn0.9Ti3O8 ceramic sintered at 950 degrees C, which make it become an attractive promising candidate for LTCC application. As x increases from 0.5 to 1, the dielectric loss significantly increases with AC conductivity increasing up to 2.3 x 10(-4) S/cm (at 1 MHz). (c) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.