  We report structural and magnetic properties studies of large high quality
single-crystals of the frustrated magnet, Nd$_2$Zr$_2$O$_7$. Powder x-ray
diffraction analysis confirms that Nd$_2$Zr$_2$O$_7$ adopts the pyrochlore
structure. Room-temperature x-ray diffraction and time-of-flight neutron
scattering experiments show that the crystals are stoichiometric in composition
with no measurable site disorder. The temperature dependence of the magnetic
susceptibility shows no magnetic ordering at temperatures down to 0.5 K. Fits
to the magnetic susceptibility data using a Curie-Weiss law reveal a
ferromagnetic coupling between the Nd moments. Magnetization versus field
measurements show a local Ising anisotropy along the <111> axes of the
Nd$^{3+}$ ions in the ground state. Specific heat versus temperature
measurements in zero applied magnetic field indicate the presence of a thermal
anomaly below $T\sim7$ K, but no evidence of magnetic ordering is observed down
to 0.5 K. The experimental temperature dependence of the single-crystal bulk dc
susceptibility and isothermal magnetization are analyzed using crystal field
theory and the crystal field parameters and exchange coupling constants
determined.
