Synthesis and growing up a new coloured crystal from an isomorphous substances by using the overgrothes phenomenon and studied its pysical , mecanical and crystallographic properties

Abstract EN

Three crystals of sulfate salt were prepared under lab environments, these are : KAl(SO4)2.12H2O, Cr2(SO4)3 and KAlCr(SO4)2.12H2O.

The physical and mechanical properties for the KAl(SO4)2.12H2O and KAlCr(SO4)2.12H2O crystals were studied.

We deal with the latter crystal which called overgrowths and prepared from the isomorphous substances (aluminum sulfate and chromium sulfate).

We prepared this crystal by insertion few Cr atoms in the same places of Al atoms in the KAl(SO4)2.12H2O cubic lattic crystal.

The crystallographic properties of an overgrothes crystal were studied.

The new crystal crystallizes in the cubic system, space grope pa-3.

The cell dimentions are : a = b = c = 12.135 AO, α = β = γ = 90o, volume of Al cell = 1786.98 * 106 pm3, volume of Al–Cr cell = 1800.26 * 106 pm3 and Z = 4 .

The volume of cell indicates that the chemical composition of the two layers of crystal are different as it shown in formula data obtained from X – Ray analysis.

The results obtained from FT-IR and UV.

Visib.

Spectrum are also support this conclusion.