Crystal growth of the non-magnetic Zn$^{2+}$ and magnetic Co$^{2+}$ doped quasi one-dimensional spin chain compound SrCuO$_{2}$ using the travelling solvent floating zone method

摘要

We report on the crystal growth of the quasi one-dimensional quantum spinchain compound SrCuO$_{2}$ and its doped variants containing magnetic cobalt(0.25%, 0.5%, 1% and 2.5%) and non-magnetic zinc (0.5\% and 1\%) impurities.Crystals are grown using the travelling solvent floating zone (TSFZ) method ina four-mirror optical furnace. Some crucial factors, key to the stability of aTSFZ process, including the choice of solvent composition and its associatedmelting behavior, are discussed in detail. The grown crystals werecharacterized using x-ray powder diffraction, scanning electron microscopy,optical microscopy, neutron single crystal diffraction and magneticsusceptibility measurements. Co-doping induces magnetic anisotropy and acorresponding change of magnetic behavior characterized by the presence of asharp peak in the magnetic susceptibility at low-temperatures (T = 5 K), whichis not seen for the pristine compound. The peak position is shown to scalelinearly with Co-concentration for low doping levels upto 2.5%.