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锆钛酸铅有机复合热释电材料的制备及性能研究

Study on the Preparation and Properties of the Pyroelectric Lead Zirconate Titanate Organic Composites

【作者】 仝金雨

【导师】 姜胜林;

【作者基本信息】 华中科技大学 , 材料物理与化学, 2006, 硕士

【摘要】 热释电红外传感器具有成本低廉、无需制冷及红外波长无选择性等优点,在红外探测和红外成像方面占有极其重要的地位,从而引起越来越多研究者的兴趣。本文采用传统的固相法制备了热释电PZT陶瓷,通过球磨制得了PZT陶瓷粉体,以传统的热压工艺制备了PZT/PVDF复合热释电材料,并系统地研究了PZT/PVDF复合热释电材料地介电、压电及热释电性,计算了其探测率优值Fd,并进一步从理论上进行了探讨。本文主要研究内容如下:采用传统的单轴拉伸工艺制备了拉伸的PVDF薄膜。结果表明最佳工艺条件是拉伸温度为80℃,拉伸比R=5,退火温度是120℃,在此条件下测得PVDF薄膜具有明显的铁电性,热释电系数p=0.3×10-8c/cm2·K,压电系数d33=9 PC/N,tanδ=0.015,εr=12。采用传统的固相法制备了热释电PZT陶瓷,通过SEM、XRD、XPS等分析方法,对其所产生的“束腰”消失现象进行了分析。研究结果表明,过量的Mn偏析于晶界,使材料的晶界具有P型导电性,偏析Mn的量越多,晶界P型导电性越强,氧缺位钉扎电畴的能力下降,电畴容易反转,从而导致“束腰”现象的消失。通过传统的热压工艺制备了0-3型PZT/PVDF复合热释电材料,运用SEM、XRD等分析手段对其表面形貌及微观结构进行了分析,详细讨论了陶瓷体积分数、极化强度和极化温度对其介电、压电、热释电的影响,结果表明,当陶瓷体积分数为0.47时,热释电系数p及探测率优值Fd均达到一个最大值,分别为9.58×10-8c/cm2·K、13.5×10-5Pa-1/2,与PZT陶瓷相比,Fd提高了35%。初步从理论上对铁电陶瓷-铁电聚合物复合热释电材料进行了研究,并分别推导出了0-3/1-3混合连通型及0-3/3-3混合连通型铁电陶瓷-铁电聚合物复合热释电材料的热释电系数的表达式。

【Abstract】 Pyroelectric infrared sensors have been extensively studied in the field of thermal detection and imaging of objects, because of the advantages of high sensitivity at long-wavelength and room-temperature operation without cooling system. The PZT pyroelectric ceramics have been prepared by traditional solid method, and the powder of the PZT is prepared by ball milling. The specimen of PZT/PVDF composites is prepared by hot press method, and the pyro, piezo, ferroelectric and dielectric properties are studied. Meanwhile, theoretic analysis has been concluded, and Fd has been calculated. The main research is listed as follow:The PVDF pyroelectric thin films are prepared by Uniaxial-Drawing. The results show that the optimum processing for preparing pyroelectric PVDF thin films: the drawing-temperature is 80℃, with the ratio of drawing at 5 and the anneal temperature at 120℃. The PVDF thin films prepared in this method have a pyroelectric coefficient p= 0.3×10-8C/cm2·K, with the piezoelectric coefficient d33 =9 PC/N, tanδ=0.015,εr =12.The pyroelectric PZT ceramics are prepared by solid method, and the vanishing phenomenon of constriction of the polarization are discussed through SEM, XRD, XPS. The results show that the grain boundary bear P type conductance because of the aggregation of the excess Mn. P type conductance has the same trend as the amount of Mn aggregation. The more the amount of Mn is, the more likelihood the domain would reverse.The pyroelectric PZT/PVDF composites of 0-3 connectivity are prepared by hot press method. The surface morphology and microstructure are discussed through SEM, XRD. The affects of the ceramic volume, the polarization temperature and the polarization voltage on the pyro, piezo and dielectric properties are discussed. The results show that when the ceramic volume reaches to 0.47, there is a maximum value of both the pyroelectric coefficient p and the detectivity figure of merits Fd , the pyroelectric coefficient p is 9.58×10-8C/cm2·K, with detectivity figure of merits Fd at 13.5×10-5Pa-1/2, comparing with the PZT ceramics, the Fd has been increased by 35%.Ferroelectric ceramic-Ferroelectric polymer composites have been studied theoretically, and the expression of pyroelectric coefficient has been deprived for 0-3/1-3 type and 0-3/3-3 type composites.

  • 【分类号】TB34
  • 【被引频次】4
  • 【下载频次】418
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