Structure, thermal expansion and optical property of alumina-rich spinel substrate

Tang, Huili; Xu, Jing; Li, Hongjun; Dong, Yongjun; Wu, Feng; Chen, Min‐Qin

doi:10.1016/j.jallcom.2008.12.140

Cited by 12 publications

(7 citation statements)

References 16 publications

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“…Here, we show the formation of single‐phase high‐alumina spinel in two types of flash experiments: one carried out in the usual way by applying an electric field and switching to constant current upon the onset of the flash, and the second, a new method where the entire experiment is carried out under current control, but where the current is increased at a constant rate. These studies of flash in multiphase ceramics may have application for processing functional as well as engineering ceramics …”

Section: Introductionmentioning

confidence: 99%

α‐Alumina and spinel react into single‐phase high‐alumina spinel in <3 seconds during flash sintering

et al. 2018

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In situ X-ray diffraction measurements at the Advanced Photon Source show that α-Al 2 O 3 and MgAl 2 O 4 react nearly instantaneously and completely, and nearly completely to form single-phase high-alumina spinel during voltage-to-current type of flash sintering experiments. The initial sample was constituted from powders of α-Al 2 O 3 , MgAl 2 O 4 spinel, and cubic 8 mol% Y 2 O 3 -stabilized ZrO 2 (8YSZ) mixed in equal volume fractions, the spinel to alumina molar ratio being 1:1.5. Specimen temperature was measured by thermal expansion of the platinum standard. These measurements correlated well with a black-body radiation model, using appropriate values for the emissivity of the constituents. Temperatures of 1600-1736°C were reached during the flash, which promoted the formation of alumina-rich spinel. In a second set of experiments, the flash was induced in a current-rate method where the current flowing through the specimen is controlled and increased at a constant rate. In these experiments, we observed the formation of two different compositions of spinel, MgO•3Al 2 O 3 and MgO•1.5Al 2 O 3 , which evolved into a single composition of MgO•2.5Al 2 O 3 as the current continued to increase. In summary, flash sintering is an expedient way to create single-phase, alumina-rich spinel. K E Y W O R D Salumina, composites, field assisted sintering technology, spinels, zirconia: yttria stabilized

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Section: Introductionmentioning

confidence: 99%

α‐Alumina and spinel react into single‐phase high‐alumina spinel in <3 seconds during flash sintering

et al. 2018

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“…Many elements can be accommodated in spinel or spinel-like structures which allows for a wide array of possible spinel formulations, and a correspondingly large flexibility for tailoring these oxides for specific applications. As such, spinels find use in many applications due to their optical, magnetic and (electro) chemical properties, examples of which are cathodes, sensors, phosphors in solid state lasers as well as catalysts, and [1][2][3][4][5][6][7][8][9] refractory [10][11][12][13][14][15]. The most common refractory spinel structure is MgAl 2 O 4 in which 8 of 64 tetrahedral sites are occupied by Mg 2+ and 16 of 32 octahedral sites are occupied by Al 3+ [9].…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, the scientists have been investigating several types of materials as mineralizer to encourage spinel formation in this process [40]. As an illustration, salt vapors were reported [5] as useful additives for formation of spinel. Fluoride ions (from AlF 3 or CaF2) were also found [41] to enhance the spinel formation by replacing oxygen in the structure.…”

Section: Introductionmentioning

confidence: 99%

Influence of nano boehmite on solid state reaction of alumina and magnesia

Zargar

Bayati

Rezaie

et al. 2010

Journal of Alloys and Compounds

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“…Tang et al reported that Mg 0.4 Al 2.4 O 4 belongs to cubic spinel-type crystal system with space group F d3m (227)[26]. All the Mg 2+ cations and a fraction of Al 3+ ions statistically occupy the tetrahedral sites, and the rest of Al 3+ cations occupy octahedral sites[30]. The doped Co 2+ ions tend to substitute for tetrahedral Mg 2+ ions, considering the ionic radius and charge.…”

mentioning

confidence: 99%

A Co2+-doped alumina-rich Mg0.4Al2.4O4 spinel crystal as saturable absorber for a LD pumped Er: glass microchip laser at 1535 nm

Jiang¹,

Zou²,

Su³

et al. 2011

Laser Phys. Lett.

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Co2+‐doped Mg0.4Al2.4O4 single crystal up to ∅︁28×40 mm3 was successfully grown by the Czochralski method. By using this crystal as saturable absorber, we have demonstrated a diode‐end‐pumped passively Q‐switched Er:glass microchip laser operating at 1535 nm for the first time to the best of our knowledge. The dependences of average output power, repetition rate and pulse energy on the incident pump power were investigated. In the passive Q‐switching regime, a maximum average output power of 22.12 mW was obtained at the incident pump power of 410 mW. The narrowest pulse width, the largest pulse energy and the highest peak power were obtained to be about 3.5 ns, 4.8 μJ, and 1.37 kW, respectively. (© 2011 by Astro Ltd., Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA) (© 2011 by Astro Ltd., Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)

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Structure, thermal expansion and optical property of alumina-rich spinel substrate

Cited by 12 publications

References 16 publications

α‐Alumina and spinel react into single‐phase high‐alumina spinel in <3 seconds during flash sintering

α‐Alumina and spinel react into single‐phase high‐alumina spinel in <3 seconds during flash sintering

Influence of nano boehmite on solid state reaction of alumina and magnesia

A Co2+-doped alumina-rich Mg0.4Al2.4O4 spinel crystal as saturable absorber for a LD pumped Er: glass microchip laser at 1535 nm

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