Fourteen university, government, and industrial laboratories prepared a total of twenty pairs of single-layer titanium dioxide films. Several laboratories analyzed the coatings to determine their optical properties, thickness, surface roughness, absorption, wetting contact angle, and crystalline structure. Wide variations were found in the optical and physical properties of the films, even among films produced by nominally the same deposition techniques.

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The new non‐centrosymmetric tin fluoride borate Sn3[B3O7]F was synthesized hydrothermally, and was characterized by single‐crystal and powder X‐ray diffraction, vibrational spectroscopy, DFT calculations, second harmonic generation (SHG) measurements, thermogravimetry, and differential scanning calorimetry. Its SHG response is about 12 times that of quartz. The compound crystallizes in the non‐centrosymmetric orthorhombic space group Pna21 with lattice parameters a=922.4(2), b=769.8(4), and c=1221.9(6) pm (Z=4). Characteristic for the structure are isolated B3O7 moieties, consisting of two corner‐sharing BO3 units and one BO4 tetrahedron. These occupy half of the octahedral voids of a slightly distorted hexagonal closest packing of Sn2+ atoms, with [SnF]+ units in the other half of the octahedral voids. Sn3[B3O7]F is transparent over a wide spectral range with a UV cut‐off edge at about 263 nm.

Materials crystallizing in highly symmetric structures are of particular interest as they display superior physical properties in many relevant technological areas such as solid oxide fuels cells (SOFCs), catalysis, or photoluminescent materials. While the rare earth molybdenum oxides RE 6 MoO 12 with the large rare earth cations RE = La to Dy crystallize in a cubic defect fluorite structure type (Fm3̅ m, no. 225), the compounds with the smaller cations RE = Tm− Lu could hitherto only be synthesized in the rhombohedral defect fluorite structure type (R3̅ , no. 148). In the following, new low temperature access to the rare earth molybdenum oxides RE 6 MoO 12−δ (RE = Tm−Lu) crystallizing in the highly symmetric cubic bixbyite structure type (Ia3̅ , no. 206) will be discussed. The three-step method comprises preparation of the rhombohedral phases by solution combustion (SC) reactions, their reduction including simultaneous structural transitions from the rhombohedral to the cubic phases, and subsequent reoxidations while preserving their cubic structures. Detailed studies on this process were performed on the compound Yb 6 MoO 12−δ using TG-DTA, XPS, EDX, and X-ray powder diffraction (XRPD) measurements. In contrast to the rhombohedral phase Yb 6 MoO 12 , which does not show any ionic conductivity, the cubic bixbyite structured compound can be classified as a promising ionic conductor. Electrochemical impedance spectroscopy (EIS) revealed that bulk and grain boundary activation energy determined to be 144.6 kJ mol −1 and 150.4 kJ mol −1 , respectively, range in the same regime as the conventional ionic conductor 8-YSZ. Furthermore, the new cubic phase Yb 6 MoO 12−δ displays improved coloristic properties (UV−Vis spectroscopy) with a yellow hue value (CIE-Lab) being enhanced from b* = 26.0 of the rhombohedral to b* = 46.1 for the cubic phase, which is relevant for the field of inorganic pigments.

The tin iodide borate Sn3[B3O7]I was synthesized via a hydrothermal synthesis and crystallizes in the centrosymmetric space group Pbca (no. 61) possessing lattice parameters of a = 1071.8(3), b = 852.3(2), and c = 2016.8(5) pm and Z = 8. Characteristic for the structure are infinite chains along the b axis, built up of three membered B3O8 rings consisting of one BO3 unit and two corner-sharing BO4 tetrahedra. The three tin cations are oriented differently: one cation is located layer-like between the infinite chains, and the other two cations show an orientation in a row with the infinite chain. In this structure, only one of the three tin cations exhibits a coordination to the halogen anion. The new centrosymmetric tin iodide borate Sn3[B3O7]I was investigated by single-crystal diffraction, vibrational spectroscopy, powder X-ray diffraction data, thermogravimetry, differential scanning calorimetry, and DFT calculations.