Growth kinetics and micromorphology of NH{sub 4}Cl:Mn{sup 2+} crystals formed in the NH{sub 4}Cl-MnCl{sub 2}-H{sub 2}O-CONH{sub 3} system

The growth kinetics and elementary growth processes on the surface of NH{sub 4}Cl:Mn{sup 2+} heterogeneous crystals formed in the NH{sub 4}Cl-MnCl{sub 2}-H{sub 2}O-CONH{sub 3} system are experimentally studied. It is found that a change in the composition of complexes in an NH{sub 4}Cl crystal from Mn(NH{sub 4}){sub 2}Cl{sub 4} {center_dot} 2H{sub 2}O to MnCl{sub 2} {center_dot} 2CONH{sub 3} leads to the occurrence of a local maximum in the kinetic curve and a change in the shape of dislocation growth centers from flat to conical. The growth kinetics of {l_brace}100{r_brace} faces of heterogeneous NH{sub 4}Cl:Mn{sup 2+} crystals is described within the Bliznakov model using the Fowler-Guggenheim adsorption isotherm, which takes into account the lateral interaction of adsorbed particles.