Nuclear gamma resonance of Sn119 and Fe57 in franckeite and cylindrite.

The NGR data indicate that the coordination symmetry and valence states of tin ions are the same in franckeite and cylindrite, but that cylindrite contains more Sn2+. Also Fe is essential to both minerals. Apparently one structural layer in both minerals contains Fe ions combined with disulphide groups S-S2-, and the other layer is composed of FeS6 octahedra. -K.A.R

Multichannel sequential pulse accumulator with a two-group memory addressing

Based on the two-group RAM IC addressing principle, a multichannel (256 channels) sequential data accumulator applying KP537RU14A RAM IC with one-bit memory (4k×1) is proposed. The channel capacity is 216-1, and the input pulse repetition frequency is up to 62 kHz

Mössbauer study of the process of the room-temperature aging of the alloy Cu79Ni14Fe7

Mössbauer spectroscopy was used to investigate the initial stage of the phase separation in the quasi-binary system Cu79Ni 14Fe7 and the subsequent transformation of the alloy structures as a result of prolonged aging at room temperature. For describing the Mössbauer spectra of ferromagnetic particles, which appear upon the spinodal decomposition in a paramagnetic matrix, a model was proposed and approved, which uses particle-size distribution in the approximation of the generalized Lifshitz-Slezov-Wagner (LSW) model and of the linear decrease of the hyperfine field at the 57Fe nuclei in the near-surface layers of spherical particles. © 2011 Pleiades Publishing, Ltd

Multichannel sequential pulse accumulator with a two-group memory addressing

Based on the two-group RAM IC addressing principle, a multichannel (256 channels) sequential data accumulator applying KP537Pυ14A RAM IC with one-bit memory (4K × 1) is proposed. The channel capacity is 216-1, and the input pulse repetition frequency is up to 62 kHz. © 1998 MAHK Hayka/Interperiodica Publishing

Differential amplitude discriminator with digital/analog control

A differential amplitude discriminator is described that can operate both with a constant threshold of discrimination (registration of the number of pulses over sequential time intervals), and in the amplitude analysis mode, when discrimination levels change automatically by the chosen value ΔU. This circuit can be applied when locking the output signals to the time of arrival of the input pulses is not required. © 1996 MAHK Hayka/Interperiodica Publishing

Effects of cation distribution and oxidation state on the electrical and magnetic properties of Ni1-xCuxFeMnO4

Ni1-xCuxFeMnO4 (x = 0-1) ferromanganites are prepared by solid-state reactions, and their structural, electrical, and magnetic properties were investigated. The results demonstrate that all of the synthesized materials are partially inverted spinels with cubic unit cells and are magnetic semiconductors. The temperature and frequency dependences of their transport properties are characteristic of hopping conduction. Mössbauer data and the results of electrical and magnetic measurements are used to assess the cation distribution in the ferromanganites studied, which are shown to contain Mn2+ in the A site and a mixture of Mn3+ and Mn4+ in the B site

Mössbauer studies of Cu1-xNi xFeMnO4 spinel ferrites

Nickel copper ferromanganites Cu1-xNi xFeMnO4 with the composition (0≤x≤1) have been prepared using a ceramic technique. A single phase of these compounds was confirmed by X-ray powder diffraction measurements. Mössbauer spectra were recorded in 20-628 K temperature range. The spectra of all samples showed two well-resolved Zeeman patterns corresponding to A- and B-sites. At room temperature the hyperfine field increases with decreasing Cu concentration. The cation distribution obtained from analysis of Mössbauer spectra revealed a partially inverse spinel structure. The Curie temperature (TC) increased with the increase of the composition parameters (x). The specific heat Cp for nucleus 57Fe was calculated from Mössbauer data for Cu0.5Ni0.5FeMnO4, and NiFeMnO 4. The temperature dependence of the hyperfine parameters was studied, for these samples. The sublattice magnetization H(T) obeys the one-third power law in the range 0.47<T/TC<0.92. © 2004 Elsevier B.V. All rights reserved

The effect of radiofrequency modulation of 57Fe hyperfine interaction by rotating magnetic field

The effect of 57Fe hyperfine interaction radiofrequency (rf) modulation by external rotating magnetic field was studied in thin Permalloy foil by means of Mössbauer spectroscopy. The rf effect was investigated as a function of intensity for several rf field frequencies. The experiments show that the external rotating rf field causes considerable changes in the hyperfine pattern. The obtained spectra are in disagreement with those obtained by Perlow [Phys. Rev. 172 (1968) 319]. They also are inconsistent with magnetostriction hypothesis. Proceeding from the Mössbauer spectrum analysis one may conclude that the magnetization of investigated foil changes its direction in a complex manner. However, the undertaken experiments show that the essential number of Mössbauer nuclei experience the rotating magnetic field influence

Traditional pottery raw materials of the Bilyarsk monocentric agglomeration

© 2015, Allerton Press, Inc. Samples of clays and fragments of archaeological ceramics from sites of the Bilyarsk monocentric agglomeration are studied by means of Mössbauer spectroscopy. It is shown that local brown and gray clays enriched with illite were used as the main raw materials in the manufacture of group VII Prikamsky–Priuralsky ceramics. It is proved that the raw material base remained unchanged and the ethnographic artisanal tradition in the manufacture of molded ceramics endured from the XIV through the XV century