Single crystal growth of spin-ladder compound La8Cu7O19 by the travelling-solvent floating zone method

• Single crystal growth of spin-ladder La8Cu7O19 by optical floating zone method.
• Novel growth scenario has been witnessed and mechanism for the same is proposed.
• Crystal structure investigated using single crystal x-ray diffraction.
• Susceptibility as a function of temperature found to be anisotropic.

Large single crystals of La8Cu7O19 have been grown using the travelling-solvent floating zone method. A rather high oxygen pressure of 9 bar in the growth chamber and a slow growth speed of 0.5 mm/h were among the most important parameters in stabilizing the growth of this incongruently melting compound. Interestingly, a novel growth scenario has been witnessed. The crystal structure of the grown La8Cu7O19 crystal has been analyzed using single crystal diffractometry to extract important structural parameters of this compound. We find that La8Cu7O19 crystallizes in a monoclinic structure with space group C2/cC2/c and has the lattice parameters a≈13.83Å, b≈3.75Å, c≈34.59Å, and β≈99.33°β≈99.33°, in good agreement with the data obtained on polycrystalline samples in the literature. The magnetization shows a highly anisotropic behavior, and an anomaly at T ≈103 K.