摘要A quasi-single-phase orthorombic Si2N2O compound is obtained by hot-pressing sintering using homogeneous precursors as raw materials under nitrogen atmosphere. The bulk hardness of orthorombic Si2N2O (o-Si2N2O) is investigated by a nanoindenter experiment; the results show that o-Si2N2O with maximal value about 19GPa has a high hardness covalent crystal besides β-Si3N4. It is discovered that the high hardness is mainly attributed to the unique crystal structure. The bridging O atoms in the o-Si2N2O are responsible for decreasing hardness. It is found that the Si-O bonds in the open tetrahedral crystal structure are more easily broken and tilted than other bonds.
Abstract：A quasi-single-phase orthorombic Si2N2O compound is obtained by hot-pressing sintering using homogeneous precursors as raw materials under nitrogen atmosphere. The bulk hardness of orthorombic Si2N2O (o-Si2N2O) is investigated by a nanoindenter experiment; the results show that o-Si2N2O with maximal value about 19GPa has a high hardness covalent crystal besides β-Si3N4. It is discovered that the high hardness is mainly attributed to the unique crystal structure. The bridging O atoms in the o-Si2N2O are responsible for decreasing hardness. It is found that the Si-O bonds in the open tetrahedral crystal structure are more easily broken and tilted than other bonds.
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2009, Vol. 26 
