Herein, a new fluorine-containing borate, BaBOF3, has been synthesized by a boric acid flux method. It possesses two types of F atoms, which are involved in the pseudo-Aurivillius type [Ba2F2]2+ layers and the unique infinite [BOF2]- chains. The first-principles calculations on the title compound were performed to elucidate the structure-property relationship.

Single crystal Na 2 Co 2 TeO 6 has been successfully grown by self-flux method, and its lattice structure and basic magnetic properties were characterized. As determined by single crystal X-ray diffraction, Na 2 Co 2 TeO 6 belongs to space group P6 3 2 2 (182) with a = b = 5.2709(2) Å, c = 11.2615(15) Å, and V = 270.95 (4) Å 3 , the crystal structure is a layered honeycomb formed by CoO 6 octahedra and the TeO 6 octahedra in the center of the honeycomb layers, and the NaO 6 octahedra are between the honeycomb layers. Magnetic susceptibility measurements indicate that the single crystal sample displays a distinct anisotropic behavior and the spin parallels the honeycomb plane (ab-plane). In a lower temperature region, a series of antiferromagnetic-like (AFM-like) phase transitions were observed, which may result from the spin reorientation of Co 2+ ions. The different magnetization behavior between the polycrystalline structure and the single crystal (with the magnetic field parallel to and perpendicular to the ab-plane) reveals obvious magnetic anisotropy of single crystal Na 2 Co 2 TeO 6 . The special honeycomb planes formed by CoO 6 octahedra and the AFM interaction inter-and intra-honeycomb planes may lead to the obvious anisotropy and complicated magnetic phase transitions.

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Materials with zero-linear compression (ZLC) and zero-area compression (ZAC) have great promise for specific applications retaining constant in specific directions or planes under external impaction. To date, no more than ten ZLC/ZAC materials have been reported, most of which have very limited working pressure ranges (< 10 GPa). Herein, we report the observation of ZLC and ZAC in Li 2 Ti(IO 3 ) 6 with a gear-spring type structure over an ultra-wide pressure range (0~40 GPa). Structural analysis from the experiment and theoretical calculation reveals that the rotatable metal coordination polyhedra (gears) and extremely compressible metal chains (springs) work together to form an exquisite mechanical unloading device with intrinsic ZLC and ZAC behavior. Moreover, Li 2 Ti(IO 3 ) 6 sets a record-wide ZLC/ZAC working pressure range (up to 40 GPa) among anisotropic compression materials. The demonstration of intrinsic and long-lasting ZLC/ZAC with a gear-spring mechanism allows shock-resistant precision optics to be applied under extreme conditions.