TiN/Al2O3纳米多层膜的共格外延生长及超硬效应

采用多靶磁控溅射法制备了一系列具有不同Al₂O₃调制层厚度的TiN/Al₂O₃纳米多层膜. 利用X射线能量色散谱、X射线衍射、扫描电子显微镜、高分辨透射电子显微镜和微力学探针表征了多层膜的成分、微结构和力学性能. 研究结果表明，在TiN/Al₂O₃纳米多层膜中，单层膜时以非晶态存在的Al₂O₃层在厚度小于1.5 nm时因TiN晶体层的模板效应而晶化，并与TiN层形成共格外延生长，相应地，多层膜产生硬度明显升高的超硬效应，最高硬度可达37.9 GPa. 进一步增加多层膜中Al₂O₃调制层的层厚度，Al₂O₃层逐渐形成非晶结构并破坏了多层膜的共格外延生长，使得多层膜的硬度逐步降低. 关键词：2O₃纳米多层膜')" href="#">TiN/Al₂O₃纳米多层膜外延生长非晶晶化超硬效应

Epitaxial growth and superhardness effect in TiN/Al2O3 nanomultilayers

TiN/Al₂O₃ nanomultilayers with various Al₂O₃ layer thicknesses were prepared by multi_target magnetron sputtering. The chemical composition, microstructure and mechanical properties of these multilayers were characterized by energy dispersive X_ray spectrometry, X_ray diffraction, high_resolution transmission electron microscopy and nanoindentation. The result raveals that under the sputtering conditions, normally amorphous Al₂O₃ is forced to crystallize at very small layer thicknesses (<1.5 nm), and grows coherently and epitaxially over TiN layers. Correspondingly, the hardness of the multilayers increases significantly and reaches a maximum value of 37.9 GPa. Further increasing in layer thickness, Al₂O₃ layers form an amorphous structure and block the coherent growth of the multilayers, and thus the hardness decreases gradually.