In our study of molten Si, th¢ energy dispersive X-ray diffraction technique revealed the redueed intensities structure factor and temperature dependent change of the nearest interatomic distance and the coordinatien nurnber as compared with the previous findings. A smal] angle scattering technique showed that there is no evidence of cluster formation in Si mclt near melting temperature against an expectation. The extended X-ray absorption fine structure spectroscopy revealed that irnpurity

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... l gallium atoms are tightly bound by three Si atoms in Si melt. A measurement of Si melt density after melting gave a clear tendency ef relaxation with an equilibration period of 3 hours. The influence of the relaxation time to gTown crystals was studied and found evident in formation of point defects. The density measurement after relaxation revealed that the anomalous change takes place in the temperature range up to 15 degress higher than the melting point, In this region, thermal expansion was calculated about an order of magnitucle lager than that in the higher temperature region. The property anomaly in the sarne ternperature range was also feund for surface tension and viscesity. Addition ofO.1% beron did not show any effbct while that ofO.1% galliurn or antimony wiped out the anomaly. We found that in highly antimony doped Si melt a volatile species of Sb20 forms in proportion to the square of Sb concentration and evaporates. Also determined are the evaporation rates of SiO and Sb!O. Electrical resisticity, thermal diffusivity and spectral emissivity were also studied and it was deduced that four electrens from each Si atom were delecalized liberated into the bulk of the melt. Conventienal cemputer simu}ation techniques were clesely checked and the result was compared with that by the X-ray fluoroscopic observation ef Si melt in a cruclble. They agreed with each other qualitatively. The calculation using the newly determined evaporation rate revealed that the experimentally found radial oxygen distribution in the crystal agreed well with the calculation result. The simulation algorism was improved by analyzing a three dimensional mesh system and introducing a computation technique called k-e model. The result of the calculation based on our new algerism was found remarkably consistent with the experimcntally determined tempcratures at some localities of Si melt in the crucible. nttmum-vent +305 ffzava-)<eintgl< 1-1