纳米多层相变薄膜的相变参数的纳米结构调控机理研究

相变存储被认为是最有希望近期应用的下一代非易失性随机访问存储技术之一，具有高密度、高速度、低功耗和长保存期等优点。基于它的类脑神经网络计算国际上也正在兴起。因而，发展相变存储具有重要的科学意义和巨大的应用价值。然而，目前的相变材料难于同时实现高速度、低功耗和长期保存等优点，因而探索同时具备这些优点的相变材料成为国际前沿研究热点。类超晶格纳米结构化是目前优化相变薄膜材料性能的重要手段之一，它交替排列两种材料组成多周期薄膜，提供更多的可控参数：薄膜厚度、两种材料薄膜厚度比和周期数。然而，目前对类超晶格纳米结构调控薄膜参数的机理认识不清，只考虑了近程界面效应。本项目提出两种长程效应：应变和电场效应，可能是调控纳米结构薄膜参数的重要效应。提出对比研究单层、单周期和多周期结构薄膜的相变行为和晶格参数变化及人工应变、电场调控单层薄膜相变行为，弄清纳米结构参数调控纳米结构薄膜相变参数的物理机理。

Phase-change storage is recognized as one of most hopeful applicable next generations of non-volatile memory technologies in near future. It has the advantages of high density, high speed, low power consumption and long data retention etc. Based on phase-change storage, brain-like neuron network computation is emerging. Consequently, the development of phase-change storage is very important in science and applications. However, incumbent phase-change materials do not have the advantages of high speed, low consumption and long retention simultaneously. Consequently, exploring the phase-change materials having those advantages simultaneously becomes active frontier focus. Superlattice-like structuring is one of important tools to optimize performance of phase-change thin film materials. It arranges two material layers alternatively and thus provides more controllable parameters, such as layer thickness, the thickness ratio of two material layers and period number. However, mechanism on nano-structure manipulation of film parameters has been unclear so far because only near-range interfacial effect is considered currently. In this project, two long-range effects, the effects of strain and electric field, are proposed possibly important in manipulating the parameters of nano-structure films. Comparative studies of phase-change performance and lattice parameters of single layer, single period and multiple period films as well as strain and electric field control of phase-change performance of single layer films are proposed to understand the mechanism on nano-structuring manipulation of phase-change parameters of nano-structure films.