SINGLE CRYSTAL OF NITRIDE CONTAINING METAL ELEMENT OF GROUP III OR IV AND METHOD FOR PREPARING THE SAME

摘要

beta -ZrNCl polycrystalline powder produced by the chemical transport method and NH4Cl were mixed at a mole ratio of 1 : 2, the resultant mixture was placed in an Au capsule (6 mm of inner diameter, 6 mm of depth) as a reaction vessel (2) and the capsule was enveloped by a table salt block having a high thermal conductivity as an electrically insulating pressure medium (6). The reaction vessel was housed, together with the table salt block, inside the carbon tubes (8) as a heater and was heated under a pressure of 3 Gpa at a temperature of 900 DEG for 2 hr using a pyrophyllite (12) as a pressure transmitting medium by means of a hexahedral pressuring apparatus. After the vessel was allowed to stand for cooling to room temperature, the Au capsule was taken out, to give a light green single crystal of ss-ZrNCl. A large single crystal was a hexagonal, transparent plate having a diameter of about 2 mm and a thickness of 0.3 mm, which reflected the structure thereof.