[en] A device is described for the analog Furier conversion of free induction decreases recorder by the pulse NMR methods. Its basic elements are: a digital storage, a generator of linearly changing voltage, a generator of sinusoidal voltage, an analog signal multiplier and a comparator. Incorporation of a digital storage in to the analog unit permits to profit from the high sensitivity of the NMR methods without using a computer. Other advantages of the analog device are low cost and simplicity in operation. The spectrum, of NMR ¹³C in a liquid crystal of n-ethoksibenziliden-n-butylaniline, obtained by the described analog device is presented

No abstract available

[en] ¹H, ⁷⁷Se and ¹³³Cs NMR spectra and times of spin-lattice and spin-spin relaxation of ¹H nuclei are measured in mono- and plycrystalline samples of cesium hydrogen selenate in a wide temperature range including phase transition into superion state. Based on the data obtained H⁺ and Cs⁺ cation diffusional motion parameters are determined. It is ascertained for the first time that phase transition into a superion phase is accompanied by the occurrance of a slow (with the frequency of the order of 10⁴ Hz) cesium ion diffusion with the contribution to its observed conductivity being negligeably low in the whole temperature area of CsHSeO₄ existence. Two different types of proton diffusion are detected in the low-temperature phase. It is shown that high conductivity in cesium hydrogen selenate in both phases is conditioned by fast proton diffusion

No abstract available

[en] A wide band pulse coherent NMR spectrometer is described. The spectrometer is intended for investigating a broad number of rare nuclei (¹³C, ¹⁵N, ²⁹Si and others) in solids using the technique of double resonance with decoupling for protons or fluorine. The spectrometer consists of two channels: a 60 MHz channel which corresponds to the proton resonance in the 14.09 kOe field, and a wideband channel (3-15 MHz) that corresponds to the Larmor frequences of the majority of rare nuclei in the same magnetic field. A brief description is given of the design of both channel transmitters and receivers. A basic circuit of the spectrometer input and matching device is presented. Accumulation of the free induction droop signal is performed with the help of a modified pulse analyzer. Fourier transformation is performed by the analog device with subsequent output to a recorder. All the spectrometer assemblies, apart from receiver output stages, use integrated circuits and transistors. The obtained spectra point to a relatively high resolution (approximately 40 Hz) and sensitivity of the spectrometer

No abstract available

[en] Using the method of double pulse nuclear-nuclear resonance chemical shifts of ₂₀₇Pb NMR in ion fluorides of bivalent lead with different crystal structures have been measured. The values of chemical shifts of ₂₀₇Pb NMR in solid solutions of PbF² - CaF², PbFCl, CsPbF³ comparatively ß-PbF² are 0+-20, 75+-50 and 675+-75 million parts respectively. Theoretical interpretation of the data obtained is carried out in the framework of the model of free ion electron shell overlapping. It is shown that the calculation results in the shift of signals in CsPbF³ and PbFCl into paramagnetic region in agreement with the experiment, however, the calculated value of shift is lower the experimental one. Possible reasons for quantitative discrepancy in the experimental and calculated values of ₂₀₇Pb NMR line shifts are pointed out

[en] Relaxation times T₁, T₂, T_1e of ¹⁹Fe nuclei and electric conductivity in rubidium and cesium polycrystal hexafluorozirconates and hafnates in the 300-800 K temperature range are measured. The observed variations of the relaxation times are stated to be conditioned by two types of fluorine nuclei motion: isotropic reorientation of ZrF₆^2- and HfF₆^2- complex anions and diffusion motion of F^- ions. Parameters of these motions are defined. These compounds are found to have high ionic conductivity at high temperatures. The highest conductivity is observed in rubidium compounds, and it approaches these 3.8x10^-1 Ohm^-1xm^-1 at 740 K. High conductivity is shown to result from rapid diffusion motion of F^- ions. Phase transitions in the investigated compounds into the high-temperature phase are found to be superioR phase transitions

No abstract available

No abstract available