Dielectric properties of potassium sodium niobate mixed system

Synthesis, Characterization and Dielectric Properties of K<SUB>1-x</SUB>Na<SUB>x</SUB>NbO<SUB>3</SUB>

“…From these figures ( Fig.1-3) and tables (Tables 1-3), it is observed that the mixed system of K 1-x Na x NbO 3 has a transition from orthorhombic to tetragonal at about 220 0 C. It is 225 0 C for KNbO 3 , 215 0 C for K 0.8 Na 0.2 NbO 3 and 205 0 C for K 0.6 Na 0.4 NbO 3 , which shows that transition temperature from orthorhombic to tetragonal shifts towards lower temperature as we increases the quantity of anti-ferroelctric material sodium niobate in the mixed system of K 1-X Na X NbO 3 , which is in agreement with previous observations [1,18]. Lattice parameters of K 1-X Na X NbO 3 for different compositions at room temperature have been shown in table-A, which shows a decrease in lattice parameters as we add antiferroelectric material NaNbO 3 in mixed system of K 1-x Na x NbO 3 ceramic.…”

“…Such effects occur in connection with the simultaneous presence of phase transition in the system, where the atomic structure of the perovskite changes either discontinuously or continuously into another form. The dielectric properties of ABO 3 perovskite structure K 1-x Na x NbO 3 for some of the compositions has been extensively studied at high temperature [1] and it shows a number of ferroelectric phases with high spontaneous polarization. The solid solution of ferroelectric KNbO3 and antiferroelectric NaNbO3 exhibits good piezoelectric properties [2,3].…”

Lead-Free Ferroelectric Ceramics with Perovskite Structure

“…7, the T O-T and T C are clearly observed, the T O-T is close to 200°C as reported in several works (Du et al, 2006;Egerton & Dillon, 1959). The Curie temperature also agrees well with that reported previously which is near to 420°C (Ringgaard & Wurlitzer, 2005;Singh et al, 2001). The dielectric constant and dielectric losses are improved when the sintering temperature is 1060 and 1080°C, but at 1100 and 1120°C the dielectric constant diminishes and tan δ increases, this is directly related with density that depends on the liquid phase formation and vacancies generated when potassium and sodium are lost.…”

Characterization of Ferroelectric Na<I><SUB>x</SUB></I>K<SUB>1&minus;<I>x</I></SUB>NbO<SUB>3</SUB> System Films Prepared by Pulsed Laser Deposition

“…1,2) According to the phase diagram for the solid solution of the Na x K 1Àx NbO 3 (NKN) system, a morphotropic phase boundary (MPB) separating two orthorhombic ferroelectric phases exists at an x of around 0.5.…”