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

Abstract Large single crystals of La 8 Cu 7 O 19 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 La 8 Cu 7 O 19 crystal has been analyzed using single crystal diffractometry to extract important structural parameters of this compound. We find that La 8 Cu 7 O 19 crystallizes in a monoclinic structure with space group C 2 / c and has the lattice parameters a ≈ 13.83 A , b ≈ 3.75 A , c ≈ 34.59 A , and 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.