Crystal growth and characterization of the dilutable frustrated spin-ladder compound Bi(Cu1−xZnx)2PO6

High quality centimeter size single crystals of Bi(Cu1−xZnx)2PO6 (x=0%, 1%, 5%) have been successfully grown by the Travelling Solvent Floating Zone (TSFZ) technique. The crystals were grown with a rate of 1 mm/h in a gas mixture of 20% O2 in Ar. Characterization of the single crystal samples by means of optical microscopy, X-ray powder diffraction, X-ray Laue diffraction, neutron diffraction and magnetization measurement are reported. The magnetic susceptibility χspin(T), measured from 2 to 300 K, passes a broad maximum around 60 K, followed by an exponential decrease towards lower T, and confirm the formation of a spin singlet ground state at low temperature. At low-temperature a paramagnetic Curie-like upturn quantitatively reflect the increasing Zn-doping level.