Pb O3 成分梯度铁电薄膜的结构及性能
STRUCTURE AND PROPERTIES OF COMPOSITIONALLY GRADED Pb O3 FERROELECTRIC THIN FILMS
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摘要: 采用Sol-Gel方法,通过快速热处理,在Pt/Ti/SiO2/Si衬底上制备出Pb (Zr, Ti) O3成分梯度薄膜。用俄歇微探针能谱仪 (AES) 对制备的上梯度薄膜进行了成分深度分析,证实其成分梯度的存在。XRD分析表明,制备的梯度薄膜为四方结构和三方结构的复合结构,但其晶面存在一定的结构畸变。介电温谱测试表明,随着温度的升高,梯度薄膜出现一个铁电-铁电相变点和两个居里点,同时出现一定的频率弥散现象。不同偏压下电滞回线的测试表明,梯度薄膜表现出良好的铁电性质。热释电性能测试表明,梯度薄膜的热释电系数随着温度的升高逐渐增加,并且其热释电系数比每个单元的热释电系数大。Abstract: Compositionally graded Pb (Zr, Ti) O3 thin films were prepared on platinum-coated silicon substrates by Sol-Gel method and rapid heat-treatment. The composition depth profile of a typical up-graded film was determined by using a combination of Auger electron spectroscopy and Ar ion etching. The results confirm that the processing method produces graded composition change. XRD analysis shows that the graded thin films possess a tetragonal and rhombohedral composite structure. The curves of C-T and tgδ-T for the down-graded Pb (Zr<em>xTi1-x)O3 thin films show an F-F phase transition temperature, two Curie temperatures and the frequency dispersion phenomenon. The hysteresis loops of the graded thin films show fine ferroelectric properties. The pyroelectric coefficients of the graded thin films gradually increase with temperature, and are higher than that of every unit thin film.