Physical Properties of (M$\text{}_{2}$Cu$\text{}_{2}$O$\text{}_{3}$)$\text{}_{m}$(CuO$\text{}_{2}$)$\text{}_{n}$ (M = Ca, Sr, Bi) Single Crystals with Bi-2212 Phase on their Surface

The structural, optical, and magnetic properties are studied in the (M$\text{}_{2}$Cu$\text{}_{2}$O$\text{}_{3}$)$\text{}_{m}$(CuO$\text{}_{2}$)$\text{}_{n}$-type single crystals with the surface on which the Bi-2212-type phase was indicated. The physical properties of such samples were interpreted to some extent by the contributions of two phases. When the secondary phases on the surface of the samples were removed by mechanical polishing or etching by Ar$\text{}^{+}$-ion plasma, the physical properties were typical of the (M$\text{}_{2}$Cu$\text{}_{2}$O$\text{}_{3}$)$\text{}_{m}$(CuO$\text{}_{2}$)$\text{}_{n}$-type crystals. The optical method was shown to be effective for indication of secondary Bi-rich phases on the surface of (M$\text{}_{2}$Cu$\text{}_{2}$O$\text{}_{3}$)$\text{}_{m}$(CuO$\text{}_{2}$)$\text{}_{n}$ samples.