关键词: 分区沉积, 线型和带型α-Si₃N₄, 准一维结构

Abstract: Large quantities of wirelike and beltlike α-Si₃N₄ quasi-one-dimension structure were synthesized via direct reaction of SiO powder with N₂ at 1450℃ using chemical vapor deposition. The wirelike α-Si₃N₄ was deposited at lower temperature region (1200℃), while the beltlike α-Si₃N₄ was deposited at higher temperature region (1450℃). The mean diameter and length of wirelike α-Si₃N₄ are about 100-300 nm and tens of micrometers, respectively. And the beltlike α-Si₃N₄ is tens of nanometers in the thickness, 300nm-2μm in the width and several micrometers to tens of micrometers in the length. HRTEM image and SAED pattern of the wirelike and beltlike α-Si₃N₄ show that they are single crystalline, and beltlike α-Si₃N₄ grows along ［210］ direction. Wirelike and beltlike α-Si₃N₄ quasi-one-dimension structure grow by the VS process. Results show that high deposition temperature and supersaturation favors the formation of beltlike quasi-one-dimension structures; while low deposition temperature and supersaturation tend to form wirelike quasi-one-dimension structures. Therefore, the morphology of microstructure materials could be controlled through regulating the deposition temperature and supersaturation in the chemical vapor deposition process. The experiment may offer reference for controlled synthesis preparation of quasi-one-dimension structures.
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Key words: region-select-deposition, wirelike and beltlike α-Si₃N₄, quasi-one-dimension structure