Phase diagram and domain structure of the Rb2 x Tl2(1− x )Cd2(SO4)3 solid solutions

From measurements of temperature dependences of the birefringence and from observations of the domain structure the x, T–phase diagram for the Rb_{2 x} Tl_{2(1? x )}Cd₂(SO₄)₃ solid solutions have been obtained. Ferroelastic domain structure and movement of phase boundaries have been studied in the course of phase transitions in Rb_{2 x} Tl_{2(1? x )}Cd₂(SO₄)₃ crystals. Possible reasons for the appearance of mechanically non-compatible (‘forbidden’) ferroelastic domain walls are given.     

Solid-state NMR study of Li-assisted dehydrogenation of ammonia borane

The mechanism of thermochemical dehydrogenation of the 1:3 mixture of Li(3)AlH(6) and NH(3)BH(3) (AB) has been studied by the extensive use of solid-state NMR spectroscopy and theoretical calculations. The activation energy for the dehydrogenation is estimated to be 110 kJ mol(-1), which is lower than for pristine AB (184 kJ mol(-1)). The major hydrogen release from the mixture occurs at 60 and 72 °C, which compares favorably with pristine AB and related hydrogen storage materials, such as lithium amidoborane (LiNH(2)BH(3), LiAB). The NMR studies suggest that Li(3)AlH(6) improves the dehydrogenation kinetics of AB by forming an intermediate compound (LiAB)(x)(AB)(1-x). A part of AB in the mixture transforms into LiAB to form this intermediate, which accelerates the subsequent formation of branched polyaminoborane species and further release of hydrogen. The detailed reaction mechanism, in particular the role of lithium, revealed in the present study highlights new opportunities for using ammonia borane and its derivatives as hydrogen storage materials.     

Prediction of Interfacial Interactions between Polymer Layers

Summary: Results of a study on polymer surface modification using heterofunctional polyperoxides are presented. A prognostic model of the polymer surface modifier efficiency was developed on the basis of obtained data. It was shown that implementation of demands to the macromolecule composition during development of new peroxide-containing modifiers in combination with sufficient peroxide group reactivity increased efficiency of the polymer surface modification.     

On metric spaces with the properties of de Groot and Nagata in dimension one

A metric space (X,d) has the de Groot property GPn if for any points x₀,x₁,…,xn+2∈X there are positive indices i,j,k?n+2 such that i≠j and d(xi,xj)?d(x₀,xk). If, in addition, k∈{i,j} then X is said to have the Nagata property NPn. It is known that a compact metrizable space X has dimension dim(X)?n iff X has an admissible GPn-metric iff X has an admissible NPn-metric.We prove that an embedding f:(0,1)→X of the interval (0,1)⊂R into a locally connected metric space X with property GP₁ (resp. NP₁) is open, provided f is an isometric embedding (resp. f has distortion Dist(f)=‖fLip_‖⋅‖f−1Lip_‖<2). This implies that the Euclidean metric cannot be extended from the interval [−1,1] to an admissible GP₁-metric on the triode T=[−1,1]∪[0,i]. Another corollary says that a topologically homogeneous GP₁-space cannot contain an isometric copy of the interval (0,1) and a topological copy of the triode T simultaneously. Also we prove that a GP₁-metric space X containing an isometric copy of each compact NP₁-metric space has density ?c.     

Syntheses and Structures of RE10Ni9+xIn20 (RE = Tb,Dy) and YbNiIn2

The ternary indides RE₁₀Ni_9+xIn₂₀ (RE = Tb, Dy) were synthesized from the elements by arc‐melting under argon and subsequent annealing. YbNiIn₂ was prepared in a sealed tantalum tube in a water‐cooled sample chamber of a high‐frequency furnace. X‐ray powder and single crystal data revealed isotypism with the tetragonal Ho₁₀Ni₉In₂₀ type structure, space group P4/nmm for the RE₁₀Ni_9+xIn₂₀ compounds: a = 1337.0(2), c = 909.5(2) pm, wR2 = 0.0527, 1795 F² values, 65 variables for RE = Tb, and a = 1333.63(7), c = 907.2(1) pm, wR2 = 0.0590, 1346 F² values, 65 variables for RE = Dy. Both indides show an additional nickel site (Ni4) with partial nickel occupancy leading to the refined compositions Tb₁₀Ni_9.34(2)In₂₀ and Dy₁₀Ni_9.32(2)In₂₀. YbNiIn₂ adopts the orthorhombic MgCuAl₂‐type structure: Cmcm, a = 430.67(9), b = 1033.0(2), c = 758.1(1) pm, wR2 = 0.0262, 424 F² values and 16 variable parameters. The crystal chemistry of the RE₁₀Ni_9+xIn₂₀ and RENiIn₂ compounds is briefly discussed.     

Synthesis and Structures of SrAuIn and SrAuIn3

The intermetallic compounds SrAuIn and SrAuIn₃ were synthesised from the elements in sealed tantalum ampoules in a high‐frequency furnace. Both indides were studied by X‐ray powder and single crystal diffraction: TiNiSi type, Pnma, a = 772.2(4), b = 478.6(2), c = 844.0(4) pm, wR2 = 0.0474, 748 F² values, 20 variables for SrAuIn and BaNiSn₃ type, I4mm, a = 456.97(8), c = 1243.7(3) pm, wR2 = 0.0381, 397 F² values, 18 variables for SrAuIn₃. The latter reveals a small degree of Au/In disorder. Both structures consist of three‐dimensional [AuIn], respectively [AuIn₃] polyanionic networks with short Au–In distances (287–291 pm in SrAuIn and 268–284 pm in SrAuIn₃. The latter indide reveals also In–In bonding (294–323 pm). The larger voids within the polyanionic networks of both structures are filled by the strontium cations.     

9‐Cyano‐10‐methylacridinium hydrogen dinitrate

The title compound, C₁₅H₁₁N₂⁺·HN₂O₆^?, crystallizes in the monoclinic space group C2/c with four mol­ecules in the unit cell. The planar 9‐cyano‐10‐methyl­acridinium cations lie on crystallographic twofold axes and are arranged in layers, almost perpendicular to the ac plane, in such a way that neighbouring mol­ecules are positioned in a `head‐to‐tail' manner. These cations and the hydrogen dinitrate anions are linked through C—H?O interactions involving four of the six O atoms of the anion and the H atoms attached to the C atoms of the acridine moiety in ring positions 2 and 4. The H atom of the hydrogen dinitrate anion appears to be located on the centre of inversion relating two of the four O atoms engaged in the above‐mentioned C—H?O interactions. In this way, columns of either anions or cations running along the c axis are held in place by the network of C—H?O interactions, forming a relatively compact crystal lattice.     

A combined diffraction and geometrical optics approach for lidar overlap function computation

We propose a new approach for computation of lidar overlap function, in which light propagation from a lidar to the atmosphere is analyzed with diffraction theory, while the backward propagation is treated with geometrical optics. In this approach, the beam pattern in the atmosphere is represented as a diffraction pattern, and the return beam pattern on the focal plane is built by ray-tracing technique to calculate the overlap function as a ratio of the intensity entering the detector surface to the total intensity on the focal plane. The proposed approach in this paper provides more accurate overlap function of a lidar system.     

A comparative study of optic phonon-like excitations in liquid mixtures and molten salts

We report a study of collective excitations in an equimolar Lennard–Jones liquid mixture KrAr and a molten salt NaCl within the parameter-free generalized collective modes (GCM) approach. It is shown that the high-frequency propagating modes in liquid KrAr and molten NaCl correspond to optic phonon-like excitations, caused by fast mass-concentration (charge in NaCl) fluctuations. Dispersion curves for optic collective excitations are discussed.     

Magneto-optical and Microwave Properties of LuBiIG Thin Films Prepared by Liquid Phase Epitaxy Method from Lead-Free Flux

Lu2.1Bi0.9Fe5O12 （LuBiIG） garnet films are prepared by liquid phase epitaxy （LPE） method on gadolinium gallium garnet （GGG） substrates from lead-free flux. Three-inch single crystal garnet films with （444） orientation and good surface are successfully fabricated. The lattice mismatch to the GGG（111） substrate is as small as 0.08%. The ferromagnetic resonance （FMR） linewidth of the film is 2AH = 2.8-5.10e, the Faraday rotation is 1.64 deg/μm at 633nm at room temperature and the optical absorption coefficient of the film is 600cm-1 in visible range and about 100-170 cm-1 when the wavelength is larger than 800 nm. The epitaxy film possesses dominating in-plane magnetization with a saturation magnetization of about 1562G. These superior optical, magnetic-optical （MO） and microwave properties of our garnet films have potential applications in both MO and microwave devices.