Dielectric and piezoelectric properties of Mn-doped (K,Na)0.96Sr0.02NbO3ceramics

✍ Scribed by Liu, T. ;Ding, A. L. ;He, X.Y. ;Zheng, X. S. ;Qiu, P. S. ;Cheng, W. X.

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 581 KB
• Volume: 203
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200622321

✦ Synopsis

Abstract

Dense, lead‐free ceramics with composition of (K~0.5~Na~0.5~)~0.96~Sr~0.02~Nb~1–x~ Mn~x~ O~3~ (x = 0, 0.01, 0.02, 0.03, 0.04) were successfully prepared by a conventional mixed‐oxide method. The X‐ray diffraction patterns revealed pure peroveskite structure after Mn doping as compared to the original composition. This was attributed to the inhibition of K^+^ volatility during the sintering process. A dielectric anomaly was observed and explained by a multiple‐cell structure resulting from Mn‐induced lattice distortion. Low loss tangent and relatively high planar electromechanical coupling factor were obtained at x = 0.02. The main parameters for the composition of x = 0.02 are: ε ^T^ ~33~/ε~0~ = 479, d ~33~ = 121 pC/N, K ~p~ = 41%, Q ~m~ = 298, tan δ = 1.6%, T ~c~ = 391 °C. The rates of resonant frequency variation, α , and planar coupling factor variation, α , with a temperature of 80 °C are –1.85% and +1.19%, respectively. This material may be suitable for applica‐ tions in ultrasonic transducers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)