Characterization and properties of new dielectric ceramics Ba5LnZnNb9O30 (Ln=La, Nd and Sm)
(1.Key Laboratory of Nonferrous Materials and New Processing Technology, Ministry of Education,Guilin University of Technology, Guilin 541004, China2.Department of Applied Physics, Chongqing University, Chongqing 400044, China)
Abstract: Three novel dielectric ceramics Ba5LnZnNb9O30 (Ln= La, Nd and Sm) were synthesized and characterized in the BaO-Ln2O3-ZnO-Nb2O5 quaternary system, which formed the filled tungsten-bronze structures. The present ceramics exhibit high dielectric constant (εr) up to 310, low dielectric loss in the level of 10？3 at 1 MHz . Meanwhile, the temperature coefficients of the dielectric constant (τε) of Ba5LnZnNb9O30 varies from ？1 390×10？6 to ？1 220×10？6/℃ as the radius of Ln3+ increases. The present ceramics are promising candidates for high dielectric constant and low loss dielectric ceramics.
Key words: dielectric ceramics; Ba5LaZnNb9O30; Ba5NdZnNb9O30; Ba5SmZnNd9O30; tungsten-bronze structure; dielectric property; electronic materials