Junji Awaka

Single-Crystal Synthesis and Structure Refinement of Na0.44MnO2

Single crystals of Na0.44MnO2 (=Na4Mn9O18) have been synthesized by a flux method at 1173 K for the first time. The crystal structure of Na0.44MnO2 has been refined by single-crystal X-ray diffraction method. The framework structure consists of double and triple rutile-type chains of edge-sharing MnO6 octahedra and a single chain of edge-sharing MnO5. The Mn-O bond distance and bond valence analyses revealed the manganese valence Mn3+/Mn4+ ordering in the Na0.44MnO2 structure.

Single Crystal Synthesis of Cubic Garnet Related-Type Li7La3Zr2O12 by a Self-Flux Method

We have successfully synthesized single-crystal samples of fast Li-ion conducting cubic Li7La3Zr2O12 with the garnet related-type structure by a self-flux method using LiNO3 at 1150°C. The as-grown Li7La3Zr2O12 crystals are colorless and transparent; they also have a polyhedral-shape with a maximum dimension of 0.15 ´ 0.10 ´ 0.10 mm3. The powder XRD pattern shows the obtained crystals have cubic Li7La3Zr2O12 structure, and the EDX analysis confirms the chemical composition of La : Zr = 3 : 2.