Si_3N_4的晶体化和ZrN/Si_3N_4纳米多层膜的超硬效应  

Crystallization of Si_3N_4 and superhardness effect of ZrN/Si_3N_4 nano-multilayers

作　　者：赵文济[1] 董云杉[1] 岳建岭[1] 李戈扬[1] 

机构地区：[1]上海交通大学金属基复合材料国家重点实验室,上海200030

出　　处：《物理学报》2007年第1期459-464,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50571062)资助的课题~~

摘　　要：研究了Si3N4层在ZrN/Si3N4纳米多层膜中的晶化现象及其对多层膜微结构与力学性能的影响.一系列不同Si3N4层厚度的ZrN/Si3N4纳米多层膜通过反应磁控溅射法制备.利用X射线衍射仪、高分辨透射电子显微镜和微力学探针表征了多层膜的微结构和力学性能.结果表明,由于受到ZrN调制层晶体结构的模板作用,溅射条件下以非晶态存在的Si3N4层在其厚度小于0·9nm时被强制晶化为NaCl结构的赝晶体,ZrN/Si3N4纳米多层膜形成共格外延生长的柱状晶,并相应地产生硬度升高的超硬效应.Si3N4随层厚的进一步增加又转变为非晶态,多层膜的共格生长结构因而受到破坏,其硬度也随之降低.The crystallization behavior of Si3N4 modulation layers in the multilayers and its influences on the micrstructure and mechanical properties of ZrN/Si3N4 multilayers were studied. ZrN/Si3N4 multilayers with different Si3N4 thickness were synthesized by reactive magnetic sputtering. The microstructure of the multilayers was characterized with X-my diffraction and high-resolution transmission electron microscopy, and a nanoindentor was introduced to measure their mechanical properties. The results show that when the thickness is less than 0. 9 nm, Si3N4, normally amorphous in the deposited state, could form a NaCl- type pseudocrystal structure due to the template effect of ZrN crystal layer. Crystallized Si3N4 layers and ZrN template layers grow epitaxialy into columnar crystals. Correspondingly, the hardness of the films was enhanced, showing a superhardness effect. Further increasing Si3N4 layer thickness, the coherent interfaces of the multilayers were damaged and Si3N4 layers become amorphous, accompanied by the decline in the hardness of the films.

关 键 词：ZrN/Si3N4纳米多层膜 外延生长 赝晶体 超硬效应 

分 类 号：O484.4[理学—固体物理]