Crystal Growth of the Nonmagnetic Zn2+ and Magnetic Co2+ Doped Quasi-One-Dimensional Spin Chain Compound SrCuO2 Using the Traveling Solvent Floating Zone Method

Abstract

We report on the crystal growth of the quasi-one-dimensional quantum spin chain compound SrCuO2 and its doped variants containing magnetic cobalt (0.25%, 0.5%, 1%, and 2.5%) and nonmagnetic zinc (0.5% and 1%) impurities. Crystals are grown using the traveling solvent floating zone (TSFZ) method in a four-mirror optical furnace. Some crucial factors, key to the stability of a TSFZ process, including the choice of solvent composition and its associated melting behavior, are discussed in detail. The grown crystals were characterized using X-ray powder diffraction, scanning electron microscopy, optical microscopy, neutron single crystal diffraction and magnetic susceptibility measurements. Co-doping induces magnetic anisotropy and a corresponding change of magnetic behavior characterized by the presence of a sharp peak in the magnetic susceptibility at low-temperatures (T = 5 K), which is not seen for the pristine compound. The peak position is shown to scale linearly with Co-concentration for low doping levels up to 2.5%.