Growth of layered Lu2Fe3O7 and Lu3Fe4O10 single crystals exhibiting long-range charge order via the optical floating-zone method

Abstract We report the controlled growth of single crystals of intercalated layered Lu 1 + n Fe 2 + n O 4 + 3 n - δ ( n  = 1,2) with different oxygen stoichiometries δ . For the first time crystals sufficiently stoichiometric to exhibit superstructure reflections in X-ray diffraction attributable to charge ordering were obtained. The estimated correlation lengths tend to be smaller than for not intercalated LuFe 2 O 4 . For Lu 2 Fe 3 O 7 , two different superstructures were observed, one an incommensurate zigzag pattern similar to previous observations by electron diffraction, the other an apparently commensurate pattern with ( 1 3 1 3 0 ) propagation. Implications for the possible charge order in the bilayers are discussed. Magnetization measurements suggest reduced magnetic correlations and the absence of an antiferromagnetic phase.