High pressure synthesis of solid material tends to increase the density,coordination number,symmetry of material and shorten bond length.The solid synthesized at a high pressure and decompressed to ambient pressure often exhibits a metastable "stretched" state,within the high pressure stability field.The crystal grown at a high pressure is of great importance with the development of high pressure technology.Crystal growth is an important factor in the material synthesis.And many methods including gas,solid and solution methods have been used to obtain various single crystals[1].Especially,flux method is an important method for crystal growth,where the components of the desired substance dissolved in a solvent(flux) grow in the process of deposit.Its advantage is that the crystal growth displays natural facets and the disadvantage is that the crystals are relatively small.Up to date,some solid materials have been successfully synthesized by high pressure flux method[2-7].