COEXISTENCE OF MAGNETISM AND SUPERCONDUCTIVITY IN R(1.4)CE(0.6)RUSR(2)CU(2)O(10-DELTA) (R=EU AND GD)

The superconducting R(1.4)Ce(0.6)RuSr(2)Cu(2)O(10-delta) materials are also magnetically ordered at T-N much greater than T-c (T-c similar t o 42. 32 and T-N similar to 180, 122 K for R=Gd and Eu, respectively). Magnetic susceptibility and Mossbauer spectroscopy show that supercon ductivity is confined to the CuO2 planes, whereas magnetism is due to the Ru sublattice. Scanning-tunneling-spectroscopy measurements reveal a superconducting gap structure for the whole sample, indicating that the materials are of single phase, which simultaneously manifest both superconductivity and magnetism.