2005 Volume 22 Issue 2 Pages 111-
Precise measurements of density and structure of undercooled molten Si by using synchrotron radiation combined with electromagnetic levitation technique have been performed to investigate the atomic structure of molten Si in a wide temperature range including the undercooling region. The shoulder in the 1 st peak of structure factor S(Q) was slightly changed with decrease of temperature. This suggests that the middle-range order in real space of molten Si is changed with the change of temperature. However, the short-range order of molten Si is not changed in temperature region from 1550 K to 1900 K. From these experimental results, we discuss the temperature dependences of the density and the structure of undercooled molten Si based on the local structure models obtained by analytical methods.