Synthesis of Chromium Borides by Solid-State Reaction between Chromium Oxide (III) and Amorphous Boron Powders

Green pigments have been synthesized. Sodium silicate, chromium oxide, lithium carbonate and quartz were used as the main raw materials to prepare (Na0.4Li0.6)CrSi2O6 emerald green pigments by solid state reaction under the non-reductive conditions. The effects of the various technological conditions, such as raw materials ratios of (Na0.4Li0.6)/Cr/Si, calcination temperature, holding time and the type of mineralizers, on the color presentation of the synthesized pigments were studied. XRD and SEM were employed to analyze the crystalline and structure of the synthesized pigments. Chroma value was used to characterize the color of the pigments. The results show that the optimized (Na0.4Li0.6)CrSi2O6 pigments with chroma value of L*=57.78, a*=-18.98~-18.68 and b* = 10.88~9.01 were obtained.

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Formation process of tungsten borides by solid state reaction between tungsten and amorphous boron

Journal of Materials Science ◽

10.1007/bf01086475 ◽

1987 ◽

Vol 22 (8) ◽

pp. 2811-2815 ◽

Cited By ~ 59

Author(s):

H. Itoh ◽

T. Matsudaira ◽

S. Naka ◽

H. Hamamoto ◽

M. Obayashi

Keyword(s):

Solid State ◽

Solid State Reaction ◽

Formation Process ◽

Amorphous Boron ◽

Tungsten Borides

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Texture Studies on Chromium Oxide Doped Catalysts

Adsorption Science & Technology ◽

10.1177/0263617487004001-212 ◽

1987 ◽

Vol 4 (1-2) ◽

pp. 131-139

Author(s):

K.M. Abd El-Salaam ◽

A.M. El-Awad

Keyword(s):

Solid State ◽

Surface Area ◽

Calcination Temperature ◽

Phase Formation ◽

Chromium Oxide ◽

Solid State Reaction ◽

Air Flow ◽

Cation Vacancies ◽

Molar Ratios ◽

Surface Nature

Physisorption of N2 gas at 77 K has been used to determine the surface area (SBET) and porosity of Cr2O3 impregnated with Li2O in molar ratios extending from 0.25 to 50 mol %. Calcination of catalysts was affected in air flow in temperature range of 473-773 K. Variation of the SBET-calcination temperature relationship was interpreted according to the possible lattice rearrangements via a solid-state reaction leading to Li2CrO4 phase formation for Li2O rich samples and by creation of cation vacancies in case of Li2O trace samples. The cumulative calculations together with Va-t plots showed a mesoporous surface nature of samples.

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Effect of pressure on the structure of Fe–N alloys formed by solid-state reaction

Journal of Materials Research ◽

10.1557/jmr.2001.0355 ◽

2001 ◽

Vol 16 (9) ◽

pp. 2583-2590 ◽

Cited By ~ 8

Author(s):

B. Yao ◽

L. Liu ◽

S. E. Liu ◽

X. Hu ◽

W. H. Su

Keyword(s):

High Pressure ◽

Solid State ◽

Boron Nitride ◽

Solid State Reaction ◽

Atmospheric Pressure ◽

Amorphous Boron ◽

Orthorhombic Structure ◽

Mechanism Of Formation ◽

Lattice Constants ◽

Cubic Structure

Fe–N alloys with crystalline structures different from those obtained at atmospheric pressure were produced by solid-state reaction between Fe and amorphous boron nitride under high pressure. Two new paramagnetic Fe–N phases were obtained at temperatures above 800 K under pressures between 2.0 and 4.0 GPa. One is of cubic structure with lattice constant of 6.114 Å, and another is of orthorhombic structure with lattice constants of a = 4 8.443, b = 4 4.749, and c 4 3.993 Å. ε–Fe3Nx with N contents of 18.1 to 21.4 at.%, which could not be obtained at atmospheric pressure, was produced at pressures of 3.0 to 4.0 GPa and temperatures of 690 to 800 K. The mechanism of formation of ε–Fe3Nx under high pressure is discussed.

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