Structural relationships were studied among ternary Laves phases in the system ZrFe2 -ZrCr2 . Among the phenomena observed was the allotropy in ZrCr 2 , which was shown to exhibit a high temperature modification of the hexagonal C14 structure type close to the melting point and a low temperature modification of the C15 cubic type. In connection with the latter observation was the fact that at 8...

Abstract The Oxidation behavior of the Al 5 Cr 12 Fe 35 Mn 28 Ni 20 high entropy alloy was investigated in air at temperatures 900 °C, 1000 °C and 1100 for 100 h isothermally. oxidation kinetics all obeys parabolic rate law with an activation energy 100.6 kJ mol ?1 . externally oxidized forming duplex layer consisted manganese oxides that overlays Mn-Cr-Fe spinel oxides. While, it observed samp...

Nanoscale, zero-valent iron is a promising reagent for in situ reduction of a variety of subsurface contaminants, but its utility in full-scale remediation projects is limited by material costs. Iron nanoparticles (20-100 nm diameter) supported on carbon (C-Fe0) were synthesized by reacting iron salts, adsorbed or impregnated from aqueous solutions onto 80 m2/g carbon black, at 600-800 degrees ...

The successful remediation of Cr contaminated soils via chemical reduction and stabilization of soluble, toxic Cr(V1) species to insoluble Cr(II1) species relies on the long term leachability and reoxidation of reduced Cr compounds. Information of Cr chemical environments is invaluable for evaluating the efficiency of proposed stabilization technologies. We describe a matrix of Fe and Cr K-edge...

Alumina nanorods were prepared from chromium-containing alumina sludge, and the effects of doping elements, such as Cr, Fe, and Mg, were researched. The results show that the crystal transformation of alumina is restricted by the doped Cr and facilitated by the doped Fe and Mg, which is transformed from θ-Al2O3 to α-Al2O3 in the calcination process. Meanwhile, the crystal transformation of alum...

Levels of selected metals Na, Ca, Mg, K, Fe, Mn, Cr, Co, Ni, Cd, Pb and Mn were estimated by flame atomic absorption spectrophotometry in groundwater samples from Kasur, a significant industrial city of Pakistan. Salient mean concentration levels were recorded for: Na (211 mg/l), Ca (187 mg/l), Mg (122 mg/l), K (87.7 mg/l), Fe (2.57 mg/l) and Cr (2.12 mg/l). Overall, the decreasing metal concen...

The photocatalytic reduction of Cr(VI) is investigated over iron(III)-based metal-organic frameworks (MOFs) structured as MIL-88B. It is found that MIL-88B (Fe) MOFs, containing Fe3-μ3-oxo clusters, can be used as photocatalyst for the reduction of Cr(VI) under visible light irradiation, which is due to the direct excitation of Fe3-μ3-oxo clusters. The amine-functionalized MIL-88B (Fe) MOFs (de...