Electric Modulus Scaling Behaviors of the Near Stoichiometric Potassium Lithium Niobate Crystal

An electric modulus analysis was adapted in the low-frequency range from 100 Hz to 1 MHz for the near-stoichiometric potassium lithium niobate (K2.83Li1.84Nb5.33O15.66, KLN43) crystal. KLN43 displayed relaxor-like dielectric behaviors at temperatures around the dielectric maximum temperature Tmax 510 C. The corresponding minima of the real and the imaginary electric moduli M0(!) and M00(!) were observed at Tmax. Dispersive behaviors of the electric modulus were observed at the temperatures below and above Tmax. At temperatures lower and higher than Tmax, the frequency-dependent imaginary modulus showed a distinct peak that collapsed into a master curve. During the diffused phase transition, there were two imaginary modulus relaxation mechanisms. The maximum angular frequency !max of the imaginary electric modulus followed the Arrhenius law. The activation energies at temperatures lower and higher than Tmax were 0.56 eV and 1.57 eV, respectively. The superposition of the two imaginary modulus peaks during the diffused phase transition of KLN43 was assumed to be due to the hopping conduction of the mobile charge carriers and/or to the rotational dielectric relaxation mechanism.bt5bt KCI Citation Count: 6