Superhyperfine interactions in Ce3+ doped LiYF4 crystal: ENDOR measurements

The first observation of the resolved Mims electron-nuclear double resonance (ENDOR) spectra from the nearby and remote nuclei of 19F and 7Li nuclei on impurity Ce3+ ions in LiYF4 crystal is reported. It shows that LiYF4:Ce3+ system can be exploited as a convenient matrix for performing spin manipulations and adjusting quantum computation protocols while ENDOR technique could be used for the investigation of electron-nuclear interaction with all the nuclei of the system and exploited for the electron-nuclear spin manipulations.Comment: 4 pages, 2 figures, 1 Table. Reported on Theor-2017 (Kazan, Russia) Conferenc

The relaxing Tl2+ defects in crystals of β-K2SO4 group

EPR of Tl2+ ions in K2SO4, Rb2SO4, Cs2SO4 crystals have been studied. Noncentrality of Tl2+ (II) ions was observed. Activation energy values of Tl(II) complexes motion were obtained. Anomalous temperature dependence of EPR line position and appearance of new EPR lines in Rb2SO4, Cs2SO4 crystals were observed

The lifetime distribution of Tl2+ defect configurations in K2SO4 crystals

The coexistenceof EPR lines corresponding to ranges of fast and slow motion of relaxing Tl2+ defects in K2SO4 crystals was observed. The coexistence was determined to come from the lifetime distribution of Tl2+ low symmetry defect configurations. The shape of the distribution was fixed

Transient Dynamics in Magnetic Force Microscopy for a Single-Spin Measurement

We analyze a single-spin measurement using a transient process in magnetic force microscopy (MFM) which could increase the maximum operating temperature by a factor of Q (the quality factor of the cantilever) in comparison with the static Stern-Gerlach effect. We obtain an exact solution of the master equation, which confirms this result. We also discuss the conditions required to create a macroscopic Schrodinger cat state in the cantilever.Comment: 22 pages 2 figure

Single-Spin Measurement and Decoherence in Magnetic Resonance Force Microscopy

We consider a simple version of a cyclic adiabatic inversion (CAI) technique in magnetic resonance force microscopy (MRFM). We study the problem: What component of the spin is measured in the CAI MRFM? We show that the non-destructive detection of the cantilever vibrations provides a measurement of the spin component along the effective magnetic field. This result is based on numerical simulations of the Hamiltonian dynamics (the Schrodinger equation) and the numerical solution of the master equation.Comment: 5 pages + 5 figures (PNG format

High-frequency EPR study of crude oils

Four different samples of crude oil were studied by means of high-frequency W-band (94 GHz) electron paramagnetic resonance (EPR) spectroscopy with the aim to develop new methods of crude oil quality control. High spectral resolution of W-band allowed to avoid an overlap of spectra contributors. The ratio K between the integral intensity of the low-field EPR component of the vanadyl complexes to that of free radical line was chosen as an attribute of each sample. Using the K-parameters and EPR spectra simulations the crude oil leaking between adjacent horizons is shown. Pulsed EPR experiments allowed detecting free radicals signals only. It is demonstrated that the extracted transverse relaxation time could be used as an additional parameter which characterizes the origin of the crude oil and nature of the oil paramagnetic centers. © Published under licence by IOP Publishing Ltd

Rotational dynamics of copper(II) amino acid complexes by EPR and NMR relaxation methods

Rotational dynamics of the copper(II) bis-complexes with glycine and L-aspartic acid has been studied by EPR and NMR relaxation methods in aqueous solutions at several temperatures. Dynamical parameters obtained by EPR were compared with nuclear magnetic relaxation dispersion (NMRD) results and were found to be in a good agreement. From EPR data dominating trans isomer for Cu(Gly)2 and cis isomer for Cu(L-Asp)2 2- was found. On the basis of distance of closest approach of protons to central ion inferred from NMRD and crystal structure data the average slope angles of axial water molecule to equatorial plane were calculated and axial coordination of only one water molecule in the Cu(L-Asp)2 2- complex was established

The possible dynamic polarization of nuclei by using coal surface paramagnetic centers

Electron paramagnetic resonance spectra of paramagnetic centers on coal surface at 4.2-300 K have been measured when the sample is in contact with 3He, 4He or oxygen gases. At low temperatures the transferred hyperfine interaction was manifested in the case 3He gas. Our experimental data support a possibility of dynamics polarization of nuclei by using coal surface paramagnetic centers. © 2003 Elsevier Science B.V. All rights reserved

Combination of EPR measurements and DFT calculations to study nitrate impurities in the carbonated nanohydroxyapatite

We demonstrate the application of the combined experimental-computational approach for studying the anionic impurities in hydroxyapatite (HAp). Influence of the carbonation level (x) on the concentration of the NO3 2- radicals in the HAp nanocrystals of Ca10-xNa x(PO4)6-x(CO3)x(OH) 2 with x in the range 0 < x < 2 and average sizes of 30 nm is investigated by different analytical methods including electron paramagnetic resonance (EPR). Stable NO3 2- radicals are formed under X-ray irradiation of nano-HAp samples from NO3 - ions incorporated in trace amounts during the wet synthesis process. Density functional theory (DFT) based calculations show energetic preference for the PO4 group substitution by NO3 - ions. Comparison of the calculated and experimental spectroscopic parameters (g and hyperfine tensors) reveals that EPR detects the NO3 2- radicals located in the positions of the PO4 group only. It is shown that with the increase in x, the carbonate ions substitute the NO3 2-/NO3 - ions. DFT calculations confirm that carbonate incorporation in HAp structure is energetically more favorable than the formation of the nitrate defect. © 2014 American Chemical Society