Physical Properties of (M2Cu2O3)m(CuO2)n(M = Ca, Sr, Bi) Single Crystals with Bi-2212 Phase on their Surface

T h e st ructur al , opt ical, and ma gnetic prop erties are studied in the ( M 2 C u2 O 3 ) m ( C uO 2 ) n -t yp e single crystals w ith the sur face on w hich the Bi-2212-typ e phase w as indicated .T he physical prop erties of such samples w ere interpreted to some extent by the contributions of two phases.When the secondary phases on the surf ace of the samples w ere remo ved by mechanical p olishi ng or etching by A r + -ion plasma, the physical prop erties were typical of the (M 2 Cu2 O3 ) m ( C uO 2 ) n -typ e crystals.T he optical metho d w as show n to b e e˜ective for indica tion of secondary Bi-rich phases on the surf ace of (M 2 C u2 O 3 ) m ( C uO 2 ) n samples.PAC S numb ers: 78.66.{w ,