We study the coherence times and perform manipulations on the lowest-energy states of trivalent cerium ion in calcium tungstate crystal. We find the phase memory time reaching 14.2 Âµs and the time of coherent manipulations reaching 0.3 Âµs in the low-temperature limit, the latter can potentially be elongated by using the rotation angle and off-resonance error correction schemes.

Full angular variations of Cu²⁺ EPR spectra in β-Mg₂V₂O₇ (MgVO) and α-Zn₂V₂O₇ (ZnVO) were recorded for orientations of external magnetic field in three mutually perpendicular planes at 120 K and 295 K, as well as in temperature range from 110 to 295 K at some chosen orientations of magnetic field. The principal values of the g²- and A²-tensors, as well as the orientations of their principal axes were determined from angular variations of EPR line positions in three mutually perpendicular planes, using a rigorous least square fitting procedure, especially adapted to the case of non-coincident principal axes of the A²-tensors for the monoclinic and triclinic point-group symmetries in MgVO and ZnVO crystals, respectively. This procedure uses the eigenvalues and eigenvectors of the spin-Hamiltonian matrix, which allows to determine the orientations of the principal axes of the g² (Zeeman) and A² (hyperfine-interaction)-tensors. It is found, that the principal values of g²- and A²-tensors of the Cu²⁺ ions are similar in the two crystals; however, the orientations of the principal axes of these tensors are significantly different from each other. This is because the Cu²⁺ ion in MgVO is 6-fold coordinated, whereas it is 5-fold coordinated in trigonal bipyramidal coordination in ZnVO. The principal values of the g²-tensor, so obtained, are exploited to determine the electronic ground state of the Cu²⁺ ion in these two crystals.

In the paper we report on the synthesis, structural and magnetic characterization and time-resolved polar magnetooptical Kerr effect studies of thin epitaxial films of the ordered L1₀-phase of FePt and FePd compounds. Time scales of the photoinduced demagnetization and magnetization recovery are found. It is shown that demagnetization of FePt and FePd films occurs on different time scales, ∼0.2 ps and ∼3 ps, respectively. This difference makes these films promising for artificial multilayer ferrimagnets with high perpendicular anisotropy suitable for all-optical fast high-capacity information storage devices.

The structures of a single V₂O₅, binary CdO-V₂O₅ and ternary CdO-V₂O₅-P₂O₅ glass systems have been investigated by means of ⁵¹V and ³¹P MAS-NMR spectroscopy. NMR spectrum of pure V₂O₅ glass has showed that the network structure is made up of VO₅ groups, as in crystalline V₂O₅. This means that only 5-fold coordination of the vanadium atom, V(5), is the predominant type in this glass. Substitution of V₂O₅ with CdO in the glass network leads to destruction of the layered VO₅ structure and as a result VO₄ tetrahedral units are formed. Vanadium is located in this situation at V(5) and V(4) sites. The difference between the feature of NMR spectra of the sample containing 30 mil % CdO and the glass of pure V₂O₅ is considered to be due to formation of both V(4) and V(5). On the other hand, cadmium orthovanadate Cd₃(VO₄)₂ building units are the main constituent of CdO rich glass (60 mol % CdO). The local structure of the ternary CdO-P₂O₅-V₂O₅ glasses contains three types of vanadium sites, which are pentavalent vanadate units (V5), tetrahedral (V4) and mixed vanadate and phosphate units (V4-O-P4). The latter represents V atoms coordinated with P atoms as the second neighbor (VO₄)P. ³¹P NMR results have showed that the concentration of nonbridging oxygen atoms (NBOs) is increased in the phosphate network with increasing CdO contents.

Liouville – von Neumann equation has been solved numerically to calculate pulsed electron paramagnetic resonance (EPR) signals rigorously in Liouville space taking into account relaxation by spin-phonon modulation of hyperfine and g tensors in single crystal and polycrystalline materials. It is illustrated here for a spin-coupled electron-nuclear system with the electron spin S=1/2 and nuclear spin I=1/2 to calculate the spin echo correlation spectroscopy (SECSY) and echo-electron-electron double-resonance (echo-ELDOR) signals. Both a single-crystal spectrum for a chosen orientation of the external magnetic field with respect to the crystal axes and powder spectrum can be calculated. The flow chart for the simulation is included. The calculations can be carried out on a PC using Matlab within a reasonable time. A software has been developed in Matlab to do these calculations, which only requires to input the parameters on a laptop equipped with Matlab software.