Chemical methods of dispergation of metallic phases
作者:B. P. Tarasov、E. E. Fokina、V. N. Fokin
DOI:10.1007/s11172-011-0193-9
日期:2011.7
The results of a cycle of works on the chemical dispergation of intermetallic compounds and alloys were summarized and analyzed. The chemical dispergation occurs in a hydrogen or ammonia atmosphere in the temperature range from 20 to 500 °C and a pressure of 0.5–2.0 MPa. The phase transformations were studied. The conditions suitable for the production of polymetallic phase powders of various degrees of dispersity were determined.
Sodium azide as a reagent for solid state metathesis preparations of refractory metal nitrides
作者:Andrew L. Hector、Ivan P. Parkin
DOI:10.1016/0277-5387(94)00314-5
日期:1995.4
Abstract Thermal initiation (∼ 300°C) of a reaction between sodium azide and anhydrous metal chlorides (LaCl3, SmCl3, TiCl3, ZrCl4, HfCl4, VCl3, TaCl5, CrCl2, WCl6 and MnCl2) in sealed evacuated ampoules rapidly produces binary metal nitrides, dinitrogen and sodium chloride. The metal nitrides were purified by trituration with methanol and characterized by powder X-ray diffraction, scanning electron
(1–3 nm)—ranging from lanthanum as one of the largest (187 pm) to scandium as the smallest (161 pm) rare-earth metal—is shown. Size, oxidationstate, and reactivity of the nanoparticles are examined (e.g., electron microscopy, electron spectroscopy, X-ray absorption spectroscopy, selected reactions). Whereas the nanoparticles are highly reactive (e.g. in contact to air and water), they are chemically stable as THF
作者:V. N. Fokin、Yu. M. Shul’ga、B. P. Tarasov、E. E. Fokina、I. I. Korobov、A. G. Burlakova、S. P. Shilkin
DOI:10.1007/s11176-005-0077-5
日期:2004.11
Treatment of intermetallic compounds LaNi5 and SmCo5 with ammonia (initial ammonia pressure 0.6– 0.7 MPa) in the presence of 10 wt% NH4Cl as an activator results in hydrogenation of these compounds or, in the case of SmCo5, in disproportionation to form Sm2Co7Hx. In some cases, the intermetallic matrix decomposes under this treatment.
作者:Dmitry M. Kuzyaev、Alexander A. Maleev、Tatyana I. Kulikova、Dmitry L. Vorozhtsov、Mikhail N. Bochkarev
DOI:10.3184/174751917x14839766277332
日期:2017.2
reaction of NdN and SmN with iodine gave the iodide-nitrides (NdI2)3N(DME)4 and (SmI)3N2(THF)2, which are inert towards sulfur, in contrast to the neodymium and dysprosium iodide-nitrides prepared by the reaction of LnI2 with N2. Reaction of NdN and SmN with C6F5OH and CpH gave the organolanthanide derivatives Ln(C5F5O)3(THF)n (Ln = Nd or Sm) and Cp3Sm with moderate and low yields, respectively. Phenylacetylene