Bi4Ti3O12铁电薄膜X射线光电子能谱研究

本文采用化学溶液沉积（ＣＳＤ）工艺在Ｓｉ（１００）衬底上制备了Ｂｉ４Ｔｉ３Ｏ１２铁电薄膜，这种薄膜的Ｘ射线衍射（ＸＲＤ）结果显示其具有较好的结晶性。运用Ｘ射线光电能谱仪（ＸＰＳ）对薄膜的结构进行了研究，分析结果表明，衬底中Ｓｉ向镀在其上的Ｂｉ４Ｔｉ３Ｏ１２膜层内扩散，影响扩散的主要因素是膜厚及退火温度。     

Controllable Synthesis of Titania Nanocrystals with Different Morphologies and Application to the Degradation of Phenol

Titania nanocrystals with different morphologies were prepared using the hydrothermal method via controlling the pH values of solution, the ratio of reactants, temperature, and time of the hydrothermal reaction. The experimental results showed that uniform rod-like titania particles with an average aspect ratio of 6：1 could be obtained under the conditions of pH=11, n（TBOT）：n（TEA）=1：2, hydrothermal treatment at 150 °C for 24 h. When pH〈10, spherical titania nanocrystals could be obtained; with increasing the pH value, the diameter became smaller. Finally, the smallest size of the particles could reach 7 nm. Nanocrystals with uniformly well-dispersed and perfect crystallographic form were obtained via the above method. Phenol was used as the degradation model for testing the photocatalytical activity of the titania nanocrystals with different morphologies.     

High-k材料研究进展与存在的问题

随着集成电路的飞速发展，SiO2作为传统的栅介质将不能满足MOSFET器件高集成度的要求，需要一种新型Hish-k材料来代替传统的SiO2，这就要综合考虑以下几个方面问题：(1)介电常数和势垒高度；(2)热稳定性；(3)薄膜形态；(4)界面质量；(5)与Si基栅兼容；(6)工艺兼容性；(7)可靠性。本文综述了几类High-k栅介质材料的研究现状及存在的问题。目前任何一种有望替代SiO2的栅介质材料都不能完全满足上述几点要求。但是，科学工作者们已经发现了几种有希望的Hihg-k候选材料。