Fabrication of Yb-doped Lu2O3-Y2O3-La2O3 solid solutions transparent ceramics by self-propagating high-temperature synthesis and vacuum sintering

The synthesis of AlN–SiC solid solutions from Si3N4, Al, and C was investigated using the induction-field-activated/self-propagating high-temperature synthesis/static pseudo-isostatic compaction technique. Careful x-ray diffraction analyses were made on the products of combustion to determine reaction routes. Optical microscopy as well as scanning electron microscopy with an electron probe microanalysis was used for microstructural analysis. It was found that initially molten aluminum reacted with silicon nitride producing an Al–Si alloy. At higher temperatures, aluminum evaporated from the Al–Si liquid and the synthesis of AlN via a vapor phase process took place. Subsequently, dissolution of AlN into molten Si resulted in the formation of an AlN–SiC solid solution from the Al–N–Si–C liquid phase. However, below 1850 °C, the resulting solid solution of 4AlN–3SiC was not fully crystallized. Combustion temperatures above or equal to 1850 °C were required to prepare a highly crystallized solid solution with a morphology exhibiting hexagonal platelets. Based on these observations, a model for the formation of AlN–SiC solid solution is proposed.

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Phase States and Dielectric Properties of Li0.17Na0.83NbуТа1 –уO3 Ceramic Solid Solutions Prepared by High-Pressure, High-Temperature Synthesis

Inorganic Materials ◽

10.1134/s0020168519050030 ◽

2019 ◽

Vol 55 (5) ◽

pp. 509-515

Author(s):

V. V. Efremov ◽

M. N. Palatnikov ◽

Yu. V. Radyush ◽

O. B. Shcherbina

Keyword(s):

High Pressure ◽

High Temperature ◽

Dielectric Properties ◽

Solid Solutions ◽

Temperature Synthesis ◽

High Temperature Synthesis ◽

High Pressure High Temperature

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Fabrication and Magneto-Optical Property of (Dy0.7Y0.25La0.05)2O3 Transparent Ceramics by PLSH Technology

Magnetochemistry ◽

10.3390/magnetochemistry6040070 ◽

2020 ◽

Vol 6 (4) ◽

pp. 70

Author(s):

Ding Zhou ◽

Xiaohui Li ◽

Tun Wang ◽

Jiayue Xu ◽

Zhanyong Wang ◽

...

Keyword(s):

High Temperature ◽

Optical Property ◽

Low Cost ◽

Optical Material ◽

Pressureless Sintering ◽

Transparent Ceramics ◽

Temperature Synthesis ◽

Verdet Constant ◽

Magneto Optical Property ◽

High Temperature Synthesis

(Dy0.7Y0.25La0.05)2O3 magneto-optical transparent ceramics were successfully fabricated by pressureless sintering in reductive H2 atmosphere (PLSH). The raw powder of (Dy0.7Y0.25La0.05)2O3 was synthesized by a modified self-propagating high-temperature synthesis (SHS) and sintered to transparent ceramics at 1400–1600 °C in a flowing H2 atmosphere, showing good sinterability of the as-synthesized raw powder. The magneto-optical Verdet constant of (Dy0.7Y0.25La0.05)2O3 transparent ceramics was measured to be −191.57 rad/(T·m) at a wavelength of 632.8 nm. In this magneto-optical material of (Dy0.7Y0.25La0.05)2O3, relative cheaper Dy and Y were used to replace Tb, and the low cost and good magneto-optical property showed the advantage of application on Faraday isolators (FIs) and Faraday rotators (FRs).

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Combustion Synthesis of (Ti,V)2AlC Solid Solutions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.909.19 ◽

2014 ◽

Vol 909 ◽

pp. 19-23

Author(s):

Chun Liang Yeh ◽

Wen Jung Yang

Keyword(s):

High Temperature ◽

Solid Solutions ◽

Reaction Front ◽

Combustion Temperature ◽

Product Formation ◽

Front Velocity ◽

Temperature Synthesis ◽

Powder Mixtures ◽

Substitution Site ◽

High Temperature Synthesis

(Ti,V)2AlC solid solutions with Al2O3 addition were produced by solid state combustion involving aluminothermic reduction in the mode of self-propagating high-temperature synthesis (SHS). Starting materials included Ti/V2O5/Al/Al4C3 and TiO2/V2O5/Al/Al4C3 powder mixtures. Attempts were made to obtain (Ti1-xVx)2AlC with a broad substitution percentage. Combustion exothermicity was increased by increasing V2O5 for the yield of a higher proportion of V at the substitution site, which not only increased the combustion temperature and reaction front velocity, but also facilitated the evolution of (Ti,V)2AlC. The Ti-containing samples showed higher reaction exothermicity and better product formation than those adopting TiO2. As a result, (Ti1-xVx)2AlC with x from 0.2 to 0.8 was produced from the samples composed of the Ti/V2O5/Al/Al4C3 mixture. The (Ti,V)2AlC/Al2O3 composites synthesized in this study exhibited a laminated microstructure with closely-stacked (Ti,V)2AlC slabs of about 0.30.8 μm.

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