(111)取向生长Pb(Zr0:95Ti0:05)O3纳米晶薄膜的铁电与热释电特性

" 在Pt/Ti/SiO2/Si基片上用溶胶-凝胶法与快速退火工艺制备了300 nm厚的锆钛酸铅Pb(Zr0:95Ti0:05)O3 (PZT95/5)反铁电薄膜．结果显示600~700 ℃晶化处理的钙钛矿PZT95/5薄膜具有高度(111)取向生长特性．薄膜的电性能测量采用金属-铁电-金属电容器结构．在20 V电压作用下,600~700 ℃晶化处理的PZT95/5薄膜显示出饱和电滞回线．在1 kHz下,600、650和700 ℃晶化的薄膜介电常数与损耗分别为519与0.028、677与0.029、987     

钇和镧掺杂氧化铝陶瓷的热导及其介电弛豫特性研究

采用氧化物固相反应法,制备出纯氧化铝陶瓷及其分别掺杂稀土元素钇和镧的陶瓷样品.测量了样品的结构、介电特性和热导性能;研究了烧结温度对掺杂不同稀土元素的陶瓷样品的性能的影响.X射线衍射结果表明1500℃烧结后陶瓷样品形成了单一的固溶体.而氧化铝的热导率达到8.60W/（m·K）,样品的介电性能稳定.我们发现掺杂Y³⁺和La³⁺的氧化铝陶瓷存在介电弛豫现象,并对该现象进行了机理分析.     

Dielectric and Pyroelectric Properties of （Pb0.50Sr0.50）TiO3 Ceramics

Lead strontium titanate （Pb0.50Sr0.50）TiO3 （PST） ceramics are prepared by the traditional ceramic processing. The dielectric constants and dielectric loss have been investigated in a temperature range from 25℃ to 300℃. The maximum dielectric constants for unpoled and poled samples are 9924 and 9683, respectively. The temperatures of phase transition for unpoled and poled samples are observed at 153℃ and 157℃, respectively. The phasetransition temperatures for unpoled and poled samples are not equal, which results from the polarization state of the domains. The remnant polarization and the coercive electric field are 18 uC/cm^2 and 6 kV/cm, respectively, from polarization-electric field （P - E） hysteresis loop. The temperature dependence of pyroelectric coefficients of the PST ceramics is measured by a dynamic technique. The dielectric constant and loss Lan δ of the poled PST ceramics are 813 and 0.010, respectively. The pyroelectric coefficients and figure of merit are 294 uC/cm^2 K and 13.6 × 10^-6 pa^-0.5, respectively, at room temperature 25℃and frequency lOOHz.