MOSSBAUER STUDY OF SR2CUO2F2+DELTA SUPERCONDUCTOR

The new oxy-fluoride Sr2CuO2F2+delta superconductor is investigated us ing Mossbauer spectroscopy of Fe. Squid Measurements show that T-c of Sr2Cu1-xFexO2F2+delta, x = 0.02, is 42 K. The presence of small quanti ties of Sr2CuO3-delta' and SrF2 is also shown by X-ray analysis and ma gnetization measurements. Using Mossbauer spectroscopy, the characteri stics of Fe at the Cu sites in the superconductor Sr-2 Cu1-xFexO2F2+de lta and magnetic Sr2CuO3-delta' are found. Mossbauer spectrum at the a mbient temperature shows three paramagnetic components. At low tempera tures, these paramagnetic components show magnetic splittings and feat ure characteristic of dynamical effects. The spectra have been analyse d incorporating the presence of relaxation effects. Copyright (C) 1996 Elsevier Science Ltd