| 摘要 |
The invention relates to a solid body which comprises and is constituted of monoclinic elementary cells in an optically used area. The inventive solid body, in every location in the optically used area, corresponds to essentially the same crystallographic system of coordinates, the solid body having at least two domains that differ in terms of their chemical composition in the optically used area. Preferably, the inventive solid body, at least in the optically used area, comprises tungstate and potassium and/or rubidium as a component of the monoclinic elementary cells. |
