Fluoride technology of obtaining REM magnetic alloys and master alloys

Rare earth permanent magnets (REPM) based on neodymium-Fe-boron system are the most promising, since they have the highest magnetic and satisfactory mechanical characteristics. The paper covers physical-chemical principles and shows the results of experimental studies of the process of obtaining REM alloys and master alloys using fundamentally new fluoride technology based on ladle calciothermal REM fluorides and Fe reduction

Basic stages of magnet production by fluoride technology

This paper presents the results of development of ecological low-waste “dry” fluoride technology of magnetic material production on the basis of rare-earth metals of the Nd-Fe-B-system. The physicochemical fundamentals are stated and the basic stages of the proposed technology are experimentally examined: the fluorination of raw material with elemental fluorine, the production of compact ingot alloys and addition alloys by the calcium-thermal out-of-furnace reduction of fluorides, the production of magnets with the help of the powder metallurgy method using mechanical or hydride grinding, as well as waste processing.</jats:p

Dithiophosphorylation of cyclic monoterpenes

New data are presented for the synthesizing terpene esters of dithiophosphoric acids and their structure. Copyright © Taylor & Francis Group, LLC

Dithiophosphoric and dithiophosphonic acids and their derivatives on the basis of thymol: Synthesis and antimicrobial activity

Biologically active dithiophosphoric and dithiophosphonic acids, their ammonium salts as well as S-silyl and S-plumbyl derivatives were prepared by the reaction of thymol with tetraphosphorus decasulfide and 2,4-diaryl 1,3,2,4-dithiadiphosphetane-2,4-disulfides. © 2013 Copyright Taylor and Francis Group, LLC

Study on the process of Fe (III) oxide fluorination

The article deals with a fundamentally new fluoride technology for obtaining fluoride materials, provides data on the kinetics of the process of fluorination of Fe oxide with fluorine, fluoride and ammonium bifluoride. The physical and chemical properties of obtained fluorides are shown: a study of the elemental composition, grain-size composition using the method of scanning electron microscopy and laser diffraction

Monoterpenoids dithiophosphates. Synthesis and biological activity

O,O-Dialkyldithiophosphoric acids adds at the double bond of the racemic camphene and (+)- limonene in the presence of Lewis acids in accordance with the Markownikoff rule with the formation of Sterpenyl esters of dithiophosphoric acids. The reaction with camphene is accompanied by the rearrangement of camphane structure to that of bornane. Addition of dithiophosphoric acid to (+)-limonene proceeds with the participation of the exocyclic double bond. Toxic and genotoxic properties of the monoterpenoid dithiophosphates were studied. © Pleiades Publishing, Ltd., 2010

Impurity breakdown and terahertz luminescence in n-GaN epilayers under external electric field

We report on the observation and experimental studies of impurity breakdown and terahertz luminescence in n-GaN epilayers under external electric field. The terahertz electroluminescence is observed in a wide range of doping levels (at noncompensated donor density from 4.5×10[sup 16] to 3.4×10[sup 18] cm[sup −3]). Spectra of terahertz luminescence and photoconductivity are studied by means of Fourier transform spectrometry. Distinctive features of the spectra can be assigned to intracenter electron transitions between excited and ground states of silicon and oxygen donors and to hot electron transitions to the donor states.Peer reviewe

РАЗДЕЛЕНИЕ ФТОРИДОВ ЦИРКОНИЯ И ГАФНИЯ СУБЛИМАЦИОННО-СОРБЦИОННЫМ МЕТОДОМ

The process of nuclear grade zirconium tetrafluoride (ZTF) production in a single decomposition stage was proposed and experimentally confirmed. To achieve this goal vapors of the source ZTF has to be run either through the layer of powdery zirconium dioxide with a height of 140–150 mm or above its layer with a length of 1000–1100 mm. The process cascade for the production of nuclear grade pure zirconium tetrafluoride and hafnium tetrafluoride with a hafnium content of over 99 % in a single decomposition stage and without any technological waste was developed and calculated. It was shown that the proposed process cascade for the single stage decomposition and enrichment of zirconium tetrafluoride and hafnium tetrafluoride allows to produce both zirconium tetrafluoride with a hafnium content of up to 0,01 wt.% from the source zirconium tetrafluoride having a hafnium content of 2,0 wt.% and hafnium concentrate containing more than 99 % of hafnium.Предложен и экспериментально подтвержден способ получения тетрафторида циркония (ТФЦ) ядерной степени чистоты за одну ступень разделения. Для этого пары исходного ТФЦ необходимо пропустить внутри слоя порошкообразного диоксида циркония высотой 140–150 мм или над его слоем длиной 1000–1100 мм. Разработан и рассчитан технологический каскад для получения ядерно-чистых ТФЦ и ТФГ с содержанием гафния более 99 % за одну ступень разделения при отсутствии технологических отходов. Показано, что предложенный технологический каскад для разделения и обогащения тетрафторидов циркония и гафния за одну ступень позволяет получить тетрафторид циркония с содержанием гафния до 0,01 мас.% из исходного ТФЦ с концентрацией гафния 2,0 мас.% и гафниевый концентрат с содержанием более 99 % гафния.