Independent superconductivity and paramagnetism in ${\mathrm{HoBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{\mathrm{z}}$

The magnetic properties of the superconductive materials ${\mathrm{HoBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{\mathrm{z}}$ and ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{\mathrm{z}}$ have been measured and compared. Both had superconductive transition temperatures $T_c$ in low magnetic fields near 90 K and exhibited nearly complete magnetic-flux exclusion. The susceptibility of the Ho-based materials followed a Curie-Weiss law both above and below $T_c$. These results give clear experimental evidence for a nearly complete decoupling of the magnetic and superconductive layers, demonstrating that the superconductivity is highly anisotropic.