Monoclinic crystal system crystal form substance and preparation method thereof

Abstract

The invention relates to the technical field of new material preparation, in particular to a monoclinic crystal system crystal form substance and a preparation method thereof. The molecular formula of the monoclinic crystal system crystal form substance is MoP2; the monoclinic crystal system crystal form substance comprises the following unit cell parameters of alpha = 90 degrees, beta = 119.192 + / -0.006 degrees and gamma = 90 degrees, the crystal form space group is C2 / m, and the crystal system belongs to a monoclinic system. According to the present invention, the limitation that the high red phosphorus vapor pressure easily causes the explosion of the quartz tube can be overcome by using the high temperature and high pressure conditions so as to prepare the MoP2 single crystal with the bottom-centered monoclinic structure, the crystal has the good crystallization quality, the single-crystal X-ray diffraction results prove that the single-crystal has the single phase, and the single-crystal X-ray diffraction results show that the single-crystal does not contain the impurities or the koelreuteria paniculata crystal.

Description

technical field [0001] The invention relates to the technical field of preparation of new materials, in particular to a monoclinic crystal form and a preparation method thereof. Background technique [0002] In recent years, due to the rich crystal structure types and novel physical and chemical properties of the metal phosphorus-rich compound TPn (T is a metal, and the value of n is 2, 2.5, 3 and 4, etc.), it has aroused extensive research interests of researchers. TP 2 It is an important system in metal phosphorus-rich compounds. In the periodic table of chemical elements, Cr, Mo and W belong to the same main group, and these three metal elements can chemically react with red phosphorus to form CrP 2 , MoP 2 and WP 2 . At present, the crystal structures of these three compounds reported in the literature are: CrP 2 It has a bottom center monoclinic structure (space group: C2 / m), MoP 2 Orthogonal structure with bottom center (space group: Cmc2 1 ). while WP 2 Ther...

AI Technical Summary

Problems solved by technology

When synthesizing metal phosphorus-rich compounds, there is a large temperature difference between the melting points of red phosphorus and metal elements. Therefore, it is necessary to slowly raise the temperature under the premise of adding a large amount of flux (such as Sn) to prevent the quartz tube from bursting, resulting in normal pressure. The sample preparation speed of the solid phase method is very slow (more than half a month)

Another point, also the most important point, is that the vapor pressure of red phosphorus is very high (4357 kPa at 590 degrees Celsius, about 41 atmospheres). risks of

Images