Measuring of short spin-spin relaxation times distributions using NQR nutation experiments.

Experiments using nutation interferograms and nutation spectra in nuclear quadrupole resonance (NQR) are used for the first time to find the distribution of short spin-spin relaxation times in powder samples. Instead of the traditional method of the inversion of the Laplace transform, the inversion of the integral transformations of nutation interferograms and nutation spectra are used in this work. The use of the distributions of NQR relaxation times can provide new information on dynamic processes in complex molecular systems in the solid state.

The study of polymorphic states of paradichlorobenzene by means of nuclear quadrupole resonance relaxometry.

The article describes the results of the experimental study of the molecular crystal of paradichlorobenzene in α- and β-phases by means of NQR-relaxometry with the inversion of Laplace transformation. The anisotropy effect of the pore space of wood on the distribution of times of the spin-lattice relaxation of p-C6H4Cl2 in the pores of pre-impregnated with the molten sample is shown. It was established that the increase in the T1 spin-lattice relaxation time of (35)Cl nucleus in the wood pores (channels) is observed in the case when the radio frequency field B1 is parallel to the tracheid's of wood.

Study of the EFG tensor at 75As nuclei in Ge-As-Se chalcogenide glasses.

Asymmetry parameters of the electric field gradient tensor at (75) As nuclei were determined for chalcogenide glassy semiconductors (CGS) of the Ge-As-Se system by comparing the experimental and simulated (75) As nuclear quadrupole resonance nutation interferograms. The electric field gradient asymmetry in CGS was analyzed, and it is believed that a structural change in these glassy semiconductors takes place at r¯ =  2.425.

PEANUT experiment in NQR spectroscopy for I=3/2.

The experiment with phase inversion and phase-inverted echo-amplitude detected nutation (PEANUT) was introduced in the nuclear quadrupole resonance (NQR). Formulas were obtained describing the NQR (I=3/2) experiment. Exemplary experiments are provided confirming the predicted particularities of the PEANUT spectra in NQR Cl-35.

Non-cyclic geometric phase of nuclear quadrupole resonance signals of powdered samples.

The non-cyclic geometric phase of ¹⁴N and ³⁵Cl NQR signals induced by the character of trajectory of nuclear magnetization motion upon pulse r.f. excitation of powdered samples is studied.