Studies On The Characteristics And Structure Transformation Of Magnesium Silicide Under High Pressure

Pressure, temperature, composition are three parameter for substance. The change of temperature and composition is the usual method to study the characters and improve the performance. We can obtain new material, which cannot be prepared atmosphere by study the state of sample at high pressure. The essential effect of pressure is to reduce inter-atomic distance, which leads to modification in lattice constants of crystalline material as well as to change in atomic positions within crystallographic cells. In general reductions of lattice spacing and force constants between atoms induce modifications in the band structures of solids and thus in electronic properties and optical properties. Thus the physical and chemical characters of substances at high pressure are quite abundant.With the development of high pressure physics and technology, high pressure physics is applied in various fields. It can provide the basis theories on the component,evaluative rules of the earth,the planet and whole celestial bodies, providing the characteristics and structure basis data about some spaceflight and nuclear blast materials under high pressure. Moreover it can help to understand the interaction between the molecule and atom, to understand the some models in normal condition by studying the materials high pressure energy spectrum and physical properties. It has the bright future on biology,chemistry,material science. So high pressure physics is very important in many fields and does a very important role.1,The structural behavior of magnesium silicide (Mg2Si) under high pressure at room temperature has been investigated up to 41.3 GPa by means of energy dispersive synchrotron X-ray diffraction technique in a diamond anvil cell (DAC). For the first time, the structures of Mg2Si under high pressure are character: phaseâ…¡is Pnma structure, phaseâ…¢is belong to P63/mmc. Knowing that the cell parameters of Mg2Si under different pressures basing on the different symmetry, we analyze the interior structure and the path of transitions.2,The structural behavior of magnesium silicide (Mg2Si) under high pressure at room temperature has been investigated up to 23.0 GPa by means of Raman technique in a diamond anvil cell (DAC). The pressure interval is small, so the phase transformation point is more accurate. The pressure-induced metallization phase transition is found to occur at about 5.3 GPa at room temperature. This phase transition has a pressure hysteresis.