Study on Hydro-thermal Processing of Cubic Boron Nitride by Laser Beam Irradiation

当solid materials are irradiated by laser beam in the presence of water，they are high temperature，further化学反应between solid materials and radicals which are produced from water isexpected. The aim of this research is to process cubic boron nitride or other ceramic materials byusing these reactions.Firstly water and which dissolving gases, such as methane，hydrogen and oxygen, were irradiated by an ArF excimer laser beam，an Ar ion laser beam and a YAG laser beam and the luminescences examined by Spectrophotometry.As the results ArF excimer laser beam can excite water and radicals such As 02 - d - 1+ d - 1， OH, H2，2 . are produced. While the other laser beams could not excite one but heat the solidmaterial.Secondly approximately 60 volume percent of a chamber was filled with water and the upperpart was filled with methane. The pressure of The methane dissolved in water was 350kPa. The gaspressure of the upper part of the chamber was 100kP…a. Then ArF excimer laser beam was focused just below the water surface. Consequently，film was deposited on the water around the beam-focus area. From a TEM image，关于30nm的小细节，在diameter are connected with each other in the mesh.Thirdly Si3N4ceramics是水和ArF演习laser beam是irradiated.虽然the ceramicswere placed 1mm away from the laser beamthe color of ceramics adjacent to the laser beam changed. ArF excimer laser beam可以excite water asmentioned above on the other hand，Ar ion laser beam不能excite water，但rather heats the ceramic material. the same Si3N4ceramics were irradiated by an Ar ion laser in both water and air. On both cases holes are formed，however the formed features are different each other and one processed in water seems to be partlyetched. This depends on the hydrothermal reaction between water and heated ceramics.这是一定的expected to process cBN which react with high temperature. cBN single crystal wasirradiated in water and vapor environments. in both cases very clear shaped holes formed。In particular one In water vapor showed high crystallinity on electron diffraction. Also crystalhabits were observed around the holes. Less

When solid materials are irradiated by laser beam in the presence of water, they are heated to high temperature, further chemical reaction between solid materials and radicals which are produced from water is expected. The aim of this research is to process cubic boron nitride or other ceramic materials by using these reactions.Firstly water and water which dissolving gases, such as methane, hydrogen and oxygen, were irradiated by an ArF excimer laser beam, an Ar ion laser beam and a YAG laser beam and the luminescences were examined by Spectrophotometry. As the results ArF excimer laser beam can excite water and radicals such as 02ィイD1+ィエD1, OH, H2, 02 and etc. are produced. While the other laser beams could not excite one but heat the solid material.Secondly approximately 60 volume percent of a chamber was filled with water and the upper part was filled with methane. The pressure of the methane dissolved in water was 350kPa. The gas pressure of the upper part of the chamber was 100kP … More a. Then ArF excimer laser beam was focused just below the water surface. Consequently, film was deposited on the water around the beam-focus area. From a TEM image, small particles of about 30nm in diameter are connected with each other in the mesh.Thirdly Si3N4 ceramics were immersed in water and ArF excimer laser beam was irradiated. Although the ceramics were placed 1mm away from the laser beam, the color of ceramics adjacent to the laser beam changed. ArF excimer laser beam can excite water as mentioned above, on the other hand, Ar ion laser beam can not excite water but rather heats the ceramic material. The same Si3N4 ceramics were irradiated by an Ar ion laser in both water and air. On both cases holes are formed, however the formed features are different each other and one processed in water seems to be partly etched. This depends on the hydro-thermal reaction between water and heated ceramics. It is also expected to process cBN which react with water at high temperature. cBN single crystal was irradiated in water and water vapor environments. In both cases very clear shaped holes were formed. In particular one in water vapor showed high crystallinity on electron diffraction. Also crystal habits were observed around the holes. Less