EN
The isostructural phases in Bi-2212-type HTSC were studied by structural and optical methods. The epitaxial intergrowth was shown to be a feature typical of single crystals composed of several isostructural phases. The physical properties of the multi-phase samples were interpreted on the basis of reference mono-phase samples. A presence of the intergrowth interface was assumed to be responsible for particular features in multi-phase samples.