Magnetization of the ferromagnetic-superconductor structures

The magnetization of a structure consisting of a thin superconducting film lying on a thin ferromagnetic substrate with uniaxial anisotropy is considered. It is shown that if a ferromagnet is in a multidomain state, then due to the presence of a superconducting film, the period of its domain structures decreases, which is caused by the increase of the magnetostatic energy of the system owing to Meissner currents. In a certain range of the constant of uniaxial anisotropy, under the action of a superconducting film, a domain structure may transform from a strip structure to the structure with closure domains. It is found that due to the nonuniform magnetic field of a multidomain ferromagnet, Abrikosov vortices may exist in a thin film only at certain parameters of the magnetic field.     

Clear-air millimeter-wave scattering

Clear-air millimeter-wave backscattering is observed experimentally by means of a high-power gyrotron generator and a superheterodyne receiver.Institute of Applied Physics, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 36, No. 10, pp. 942–944, October, 1993.     

Accurate Calculations on Dielectronic Recombination Resonances in Cu-like Pb

Dielectronic recombination of Pb⁵³⁺ has been studied and a resonance is detected only ∼0.1 meV above the ground state. The possibility to determine the 4p _1/2−4s _1/2 energy splitting with a similar accuracy from the determination of the resonance position is discussed. Such a precision can only be achieved by calculations which treat QED in a many-body environment at levels which can still not be reached. A fully relativistic many-body calculation of the splitting is described and the uncertainties are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Magnetization dynamics of molecular magnets in a circular polarized electromagnetic wave of millimeter range

The appearance of magnetization in a crystal of molecular magnets under the action of a circular polarized electromagnetic wave of millimeter range is considered. The time dependence of magnetization is obtained for the case of resonance and for approximation of the single relaxation time.     

Organic acid, tocopherol, and phenolic compositions of some Turkish grape cultivars

The organic acid, tocopherol, and phenolic compositions of three different grape cultivars, Emir, Kalecik karasi, and Narince were studied in order to evaluate their nutritive values and the contents of natural antioxidants. Organic acids, tocopherols, phenolic acids, flavonoids, and trans-resveratrol contents were analyzed by high-performance liquid chromatography (HPLC). In addition, pH, soluble solid, titratable acidity, and total phenolic contents were also determined. It was determined that the contents of organic acids, tocopherols, and phenolic compounds were changed according to the cultivars. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 128–130, March–April, 2006.     

Influence of Doping Different Rare Earth Ions on the Luminescence of CaTiO3‐based Phosphors

This paper reports the Gd³⁺, Dy³⁺, Tb³⁺ and Lu³⁺ doped CaTiO₃ based phosphors were synthesized by modified solid‐state reaction method and its crystal structure and luminescent properties were investigated. The X‐ray diffraction patterns (XRD) showed that the phosphors sintered at 1000 °C for 2 h were a pure CaTiO₃ phases. The optimization of reaction conditions were carried out by thermal gravimetry and differential thermal analysis methods (DTA/TG). Surface and elemental analyses were performed by using on SEM instrument. The excitation and emission spectras were recorded by photoluminescence spectrophotometer (PL).     

Synthesis and phosphorescence properties of Dy3+ and (Pr3+–Dy3+) in MgTiO3

Using tetra-n-butyl titanate and magnesium nitrate as raw materials, Dy³⁺ and Pr³⁺ ions in the matrix of magnesium titanate (MgTiO₃) was successfully synthesized by a modified solid-state reaction. The mixtures to achieve a solid-state reaction were heated in porcelain crucibles at 600?°C for 2?h, 900?°C for 6?h, and 1000.0?°C for 2?h. The reaction products obtained in an air atmosphere were characterized by X-ray powder diffractions. The optimization of reaction conditions were carried out by thermal gravimetry and differential thermal analysis methods. Surface and elemental analyses were performed by using on SEM instrument. The excitation and emission spectra were recorded by photoluminescence spectrophotometer.     

Characteristics of coherent population trapping in multilevel systems for magnetometry in plasma research

An analysis is presented of the feasibility of measurements of local poloidal magnetic fields in toroidal magnetic fusion devices using coherent population trapping (CPT) in hydrogen-like probing atoms. A measurement scheme is examined in which CPT suppresses the resonance fluorescence from a probing beam of light neutrals with Zeeman-split levels. Feasibility requirements for CPT in three- and five-level systems are discussed. As a result, a theory of CPT-based magnetometry is developed for a system significantly more complex than the conventional three-level Λ system. A theoretical analysis shows that this technique can be used to measure a local safety factor in a toroidal device to an accuracy of a few percent.     

Structural and Optical Properties of Sol-Gel Deposited Proton Conducting Ta2O5 Films

Proton conducting tantalum oxide films were deposited on ITO (Indium Tin Oxide) coated glass, fused silica and soda-lime glass substrates by spin coating using a sol-gel process. The coating solutions were prepared using Ta(OC₂H₅)₅ as a precursor. X-ray diffraction studies determined that the sol-gel films, heat treated at temperatures below 400°C, were amorphous. Films heat treated at higher temperatures were crystalline with the hexagonal δ-Ta₂O₅ structure. The solar transmission values (T _s ) of tantala films on glass generally range from 0.8–0.9, depending on thickness. The refractive index and the extinction coefficient were evaluated from transmittance characteristics in the UV-VIS-NIR regions. The refractive index values calculated at λ=550 nm increased fromn=1.78 to 1.97 with increasing heat treatment from 150 to 450°C. The films heat treated at different temperatures showed low absorption, with extinction coefficients of smaller thank=1×10⁻³ in the visible range. Impedance spectroscopic investigations performed on Ta₂O₅ films revealed that these films have a protonic conductivity of 3.2×10⁻⁴S/m. The films are suitable for proton conducting layers in electrochromic (EC) devices.