crystal structure

Phase relations in the Tl5Te3-Tl9SbTe6-Tl9TbTe6 system

Phase relations in the Tl5Te3-Tl9SbTe6-Tl9TbTe6 system were experimentally studied by DTA, XRD technique and microhardness measurements. Several isopleth sections and isothermal section at 760 K, as well as projections of the liquidus and solidus surfaces were constructed. It is determined that the system is characterized by an unlimited solubility of components in the solid state.

Regularities in the Crystal Structures of Heterocationic Octacyanometallates(IV) Molybdenum and Tungsten

A review of the crystal structures of octacyanomolybdates(IV) and octacyanotungstates(IV) of {[K(H2O)][Ln(H2O)4][M(CN)8]•2H2O}n (M4+ = Mo and Ln3 + = Y, La, Sm, Gd, Yb, M4+ = W and Ln3+= Tb, Dy, Ho, Er, Lu) composition has been done. These compounds have 3D-structures and contain infinite chains –C≡N–M–N≡C–Ln–, which extend in three dimensions, unlike CeH3O[W(CN)8]•6H2O, which has 2D-structure. The coordination polyhedra [M(CN)8]4- (M4+ = Mo, W) is different (dodecahedron, square antiprism, bicapped trigonal prism), depending on the nature of the rare-earth elements.

Crystal Structure of the Ternary Compound ErRe0.25Ge2

An alloy of nominal composition Er30.8Re7.7Ge61.5 was synthesized by arc melting and investigated by X-ray powder diffraction. A new ternary germanide of approximate composition ErRe0.25Ge2 was found, which adopts the structure type CeNiSi2 (Pearson symbol oS16, space group Cmcm, a = 4.0997(4), b = 15.7348(18), c = 3.9921(5) Å, RB = 0.0355, refined composition ErRe0.23(2)Ge2, for the as-cast alloy; a = 4.1117(3), b = 15.6846(15), c = 4.0184(3) Å, RB = 0.0420, refined composition ErRe0.28(2)Ge2, after annealing at 1073 K).

The Effect of Cooling Rate during Crystallization on the Melting Behavior of Polypropylenes of Different Chemical Structure

The melting behavior of polypropylenes of different chemical structure (isotactic homopolypropylene, propylene-based block and random copolymers and maleic anhydride grafted polypropylene) was studied by differential scanning calorimeter (DSC) and optical microscopy. Melting behavior and the crystal structure of polypropylene and its copolymers were observed depending on the crystallization rate, chemical nature of co-monomer unites and regularity of co-monomer units arrangement in the polypropylene main chain.