Free radicals in the original and sterilized caraway, curry, curcuma and cardamom were studied. An X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy was the experimental technique. Effect of microwave power in the range of 2.2-70 mW on amplitudes, linewidths, and lineshape parameters of the EPR spectra was tested. Free radicals concentrations in the non- and sterilized herb sa...

We report an electron paramagnetic resonance investigation of the grain size effects on the polaron transport in the paramagnetic regime of nanosized La2/3Ca1/3MnO3 manganites. The temperature dependences of the EPR integral intensity were analyzed in terms of spin–spin exchange interaction and small polaron hopping scenarios. The polaron activation energy decreases with the reduction of the gr...

We show that in cubic crystals with anisotropic impurity centers the sum of squares magnetic resonance [electron paramagnetic (EPR)] frequencies is invariant respect to field direction. The connection between such an and $g$-tensor components derived for different types centers. established regularity confirmed experimentally spin-noise spectra a $\mathrm{Ca}{\mathrm{F}}_{2}\ensuremath{-}{\math...

High-frequency pulse electron paramagnetic resonance (EPR) and nuclear double (ENDOR) were used to clarify the electronic structure of color centers with an optically induced high-temperature spin-3/2 alignment in hexagonal 4H-, 6H- rhombic 15R- silicon carbide (SiC) polytypes. The identification is based on resolved ligand hyperfine interactions carbon nearest, next nearest more distant neighb...

Pulsed electron paramagnetic resonance (EPR) spectroscopy is a valuable technique for the precise determination of distances between paramagnetic spin labels that are covalently attached to macromolecules. Nitroxides have commonly been utilised as paramagnetic tags for biomolecules, but trityl radicals have recently been developed as alternative spin labels. Trityls exhibit longer electron spin...

A simple strategy to separate overlapping electron paramagnetic resonance (EPR) signals in biological systems is presented. Pulsed EPR methods (inversion- and saturation-recovery) allow the determination of the T(1) spin-lattice relaxation times of paramagnetic centers. T(1) may vary by several orders of magnitude depending on the species under investigation. These variations can be employed to...

Abstract X irradiation of sucrose single crystals at room temperature leads to the production of stable radicals, which give rise to the dosimetric electron paramagnetic resonance (EPR) signal. In the first few hours after irradiation, however, the shape of the EPR spectrum changes drastically. Based on two-dimensional field-frequency electron nuclear double resonance (FF-ENDOR) measurements, w...

We present detailed angle-dependent single crystal electron paramagnetic resonance (EPR) data for field rotations in the hard plane of the S=10 single molecule magnet Mn(12)-acetate. A clear fourfold variation in the resonance positions may be attributed to an intrinsic fourth-order transverse anisotropy (O(4)/(4)). Meanwhile, a fourfold variation of the EPR line shapes confirms a recently prop...

EPR spectroscopy, in a constant-frequency field-swept experiment, was used to determine the resonant magnetic field, g-factor, line width, and hyperfine constant for diphenyl picrylhydrazyl at room temperature manganese (II) chloride cryogenic temperatures (using liquid nitrogen). Diphenyl determined be free radical, indicated by g-factor of 2.022, with field 3.23 kG microwave frequency 9.14 GH...