On a biphononic origin of the 1125 cm^(-1) absorption band in cuprous oxide

We report on the IR spectroscopic studies in both reflection (50-900 cm^{-1}) and transmission (900-3000 cm^{-1}) mode of the vibration spectrum of the cuprous oxide. A detailed analysis based on a comparison of the temperature dependences of the absorption band at 1125 cm^{-1} and of IR and Raman active fundamental vibrations results in assignment of the former to a biphonon.Comment: 5 pages, 5 figures (to appear in Phys.Lett. A

2,9-Bis(trichloro­meth­yl)-1,10-phenanthroline1

The asymmetric unit of the title compound, C14H6Cl6N2, contains two crystallographically independent mol­ecules, each of which is slightly twisted from planarity. The dihedral angles between the central ring and the two outer rings are 3.81 (7) and 4.30 (7)° in one mol­ecule, and 4.13 (8) and 4.10 (7)° in the other. In the crystal structure, mol­ecules are inter­linked by C—Cl⋯Cl inter­actions into sheets parallel to the ac plane. These sheets are stacked along the b axis in such a way that the mol­ecules are anti­parallel; they are further connected into a supra­molecular network. There are no classical hydrogen bonds. C⋯Cl [3.637 (2) Å], Cl⋯Cl [3.5639 (5)–3.6807 (8) Å] and Cl⋯N [3.3802 (15)–3.4093 (15) Å] short contacts and π–π inter­actions, with centroid–centroid distances in the range 3.5868 (9)–3.7844 (9) Å, are observed

Magnetic, Electric and Optical Properties of Ion Doped CuCr2O4 Nanoparticles

The magnetic, electric and optical properties of pure and ion doped CuCr2O4 - bulk and nanoparticles are investigated theoretically. The magnetization Ms and the band gap Eg decrease with increasing particle size. By Co ion doping Ms and the polarization P show a maximum whereas by Pr ion doping they decrease with increasing the doping concentration. The dielectric constant decreases with enhancing Pr dopants. It is shown that the difference between the doping and host ions radii leads to appearing of a compressive or tensile strain and to different exchange interaction constants in the doped state. Eg decreases by Co doping, whereas it increases by Pr doping

Magnetic, Electric and Optical Properties of Ion Doped CuCr₂O₄ Nanoparticles

The magnetic, electric and optical properties of pure and ion doped CuCr2O4 - bulk and nanoparticles are investigated theoretically. The magnetization Ms and the band gap Eg decrease with increasing particle size. By Co ion doping Ms and the polarization P show a maximum whereas by Pr ion doping they decrease with increasing the doping concentration. The dielectric constant decreases with enhancing Pr dopants. It is shown that the difference between the doping and host ions radii leads to appearing of a compressive or tensile strain and to different exchange interaction constants in the doped state. Eg decreases by Co doping, whereas it increases by Pr doping

Local spin excitations in the rectangular ferromagnetic semiconductor nanowires

A Green function analysis is used to study spin-waves excitations in a ferromagnetic semiconductor nanowires. The expressions of Green function for different spins of ferromagnetic nanowires are derived. The nanowire is modeled as having a cubic cross section. The results are illustrated numerically for a particular choice of parameter