Ferromagnetism of compounds with hexagonal symmetry

The concept of strong interaction in the same unit cell is used to establish the possible existence of ferromagnetism in hexagonal Co and manganese compounds: MnAs, MnSb, and MnBi. A phase diagram is constructed for the existence of ferromagnetic ordering and it is established that the Curie temperature depends on the occupancy of the transition-element 3d-shell.     

Synthesis and properties of new fullerene C60 derivatives,containing acetonide and polyol fragments

New mono- and hexa-methanofullerenes containing different number of acetonide groups are synthesized and characterized. Removing the acetonide protection leads to new chromatographically pure water-soluble polyol methanofullerenes with essentially quantitative yields.     

Conformational polymorphs of 22‐cyano‐N‐methyl‐5‐phenylpent‐2‐en‐4‐ynamide

Although the two polymorphic modifications, (I) and (II), of the title compound, C₁₃H₁₀N₂O, crystallize in the same space group (P2₁/c), their asymmetric units have Z′ values of 1 and 2, respectively. These are conformational polymorphs, since the mol­ecules in phases (I) and (II) adopt different rotations of the phenyl ring with respect the central 2‐cyano­carboxy­amino­prop‐2‐enyl fragment. Calculations of crystal packing using Cerius² [Molecular Simulations (1999). 9685 Scranton Road, San Diego, CA 92121, USA] have shown that (I) is more stable than (II), by 1.3 kcal mol^?1 for the crystallographically determined structures and by 1.56 kcal mol^?1 for the optimized structures (1 kcal mol^?1 = 4.184 kJ mol^?1). This difference is mainly attributed to the different strengths of the hydrogen bonding in the two forms.     

Crystallization and properties of CrSi2 single crystals grown from a tin solution-melt

Using the solution-melt method combined with the Bridgman method, CrSi₂ single-crystal needles and single-crystal tubes are grown at a temperature lower than their melting (crystallization) temperature. Microcrystals thus grown feature an anomalously high thermal emf. The growth of CrSi₂ single-crystal tubes is an important step forward in the production of various devices based on high-temperature thermoelectric materials.     

Convective noise in molecular electronic transducers of diffusion type

Noise in molecular electronic transducers is experimentally studied in the absence of a working fluid integral flow in the channel. It is concluded that noise in these systems is of a convective nature at low frequencies. It is found that the noise reduced to the input noise signal is independent of differences in the design of the electrode unit of the transducer.