ANISOTROPIC MAGNETIC-PROPERTIES OF SUPERCONDUCTING TETRAGONAL HOBA2CU3O7-DELTA

Small single crystals of HoBa2Cu3O7−δ have been grown and were found to be tetragonal and superconducting with a transition temperature of 93.5K. Experiments on RF field exclusion as a function of temperature and of do magnetization in fields up to 6T show anisotropy depending the relative orientation of the crystallographic ab plane and the applied B field. The RF measurements are not described by a simple BCS model with a characteristic length equal to the expected penetration depth. The magnetization measurements indicate critical currents considerably smaller for fields in the ab plane than for fields normal to the ab plane. © 1990, Elsevier Science Publishers B.V. (North-Holland). All rights reserved.