摘要
Lead-free （Na0.5K0.5）NbO3-xmol% ScTaO4 （x=0-1.5） ceramics are prepared using the conventional solid-state reaction method and their properties are investigated in detail. The results indicate that the piezoelectric properties and density are improved by the introduction of ScTaO4. Due to the high orthorhombic-tetragonal phase transition temperature TO-T （around 200°C）, stable piezoelectric properties against temperature are obtained. In a wide temperature range of 15-160°C, kp of the （Na0.5K0.5）NbO3-0.5mol% ScTaO4 ceramic remains almost unchanged and d31 increases slightly from 59pC/N to 71pC/N. The deliquescent problem is effectively solved by the addition of ScTaO4. The piezoelectric properties of ScTaO4 modified （Na0.5K0.5）NbO3 ceramics show no obvious reduction and dielectric loss increases slightly after 120h of immersion. From the analysis, it is suggested that the density is an important factor that improves the humidity resistance of the specimens.
Lead-free （Na0.5K0.5）NbO3-xmol% ScTaO4 （x=0-1.5） ceramics are prepared using the conventional solid-state reaction method and their properties are investigated in detail. The results indicate that the piezoelectric properties and density are improved by the introduction of ScTaO4. Due to the high orthorhombic-tetragonal phase transition temperature TO-T （around 200°C）, stable piezoelectric properties against temperature are obtained. In a wide temperature range of 15-160°C, kp of the （Na0.5K0.5）NbO3-0.5mol% ScTaO4 ceramic remains almost unchanged and d31 increases slightly from 59pC/N to 71pC/N. The deliquescent problem is effectively solved by the addition of ScTaO4. The piezoelectric properties of ScTaO4 modified （Na0.5K0.5）NbO3 ceramics show no obvious reduction and dielectric loss increases slightly after 120h of immersion. From the analysis, it is suggested that the density is an important factor that improves the humidity resistance of the specimens.
基金
Supported by the National Natural Science Foundation of China under Grant Nos 50802038 and 50902087, the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant Nos 20070422059 and 20080422003, the Outstanding Youth Scientist Research Foundation of Shandong Province under Grant No 2008BS04002, and the China Postdoctoral Science Foundation under Grant No 20080431199.
