Silicon carbide is a typical layer compound. Up to the present more than 150 polytypes of SiC are known. The author has developed a special Laue method which is very efficient in identifying polytypes of SiC. Using this method, we have found eightyfive new polytypes of SiC. In order to determine the crystal structure of some of these new polytypes, oscillation method and Weissenberg method have been tried but without success, because only diffraction spots of the basic polytypes 6H, 15R and 8H can be found in these photographs. This is possibly due to the smallness of these new polytypes in bulk crystals and also to the fact that these tiny polytypes are imbedded in a large 6H or 8H, 15R polytypes. A modified laue method to determine the crystal structure of SiC polytypes is developed, as well as a method for calculating the diffraction intensity of laue spot. The calculation of structure factor Fhkl in [(33)m32]3, [(33)m34]3, [(22)m23]3 and [(44)m43]3 structure families is simplified. Using this method, the crystal structure of nine new polytypes of silicon carbide have been determined. The crystal structure of these new polytypes can be designate by the Z stacking sequences (Жданов notation) as follows, 231R:[(33)1232]3,249R:[(33)1332]3,321R:[(33)1732]3, 339R:[(33)1832]3,237R:[(33)1234]3,417R:[(33)2234]3, 453R:[(33)2434]3,93R:[(44)343]3,261R:[(44)1043]3.
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