Oh groups in corundum crystals which were grown with the verneille technique

Volynets, F. K.; Sidorova, E. A.; Stsepuro, N. A.

doi:10.1007/bf00618972

Cited by 13 publications

(15 citation statements)

References 2 publications

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“…One can see that hydrogen concentration measured on the same samples but using method of IR absorption show very low hydrogen concentration. This is in agreement with previously reported results for hydrogen content in sapphire crystals measured by the same method of IR absorption [13][14][15]. The NMR method should be considered as a direct method to measure the quantity of hydrogen protons regardless of the position that the hydrogen atom can occupy in aluminum oxide lattice.…”

Section: Impurity Measurement Resultssupporting

confidence: 92%

“…One would expect that Verneuil grown sapphire would have very high hydrogen concentration due to the growth process that evolves hydrogen-oxygen flame. But surprisingly it was reported by many researchers that hydrogen concentration in Verneuil grown sapphire measured by method of IR absorption reaches only couple of ppm [13,14]. The same low level of hydrogen concentration was also found in the naturally formed corundum crystals if measured using the same method of IR absorption [15].…”

Section: Measurement Techniquesmentioning

confidence: 74%

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Hydrogen effect on the properties of sapphire

Mogilevsky

Sharafutdinova

Nedilko

et al. 2009

Window and Dome Technologies and Materials XI

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Sapphire is a widely used material for optical, electronic and semiconductor applications due to its excellent optical properties and very high durability. Optical and mechanical properties of sapphire depend on many factors such as the starting materials that are used to grow crystals, methods to grow sapphire crystals, etc. Demand for highest purity and quality of sapphire crystals increased ten fold for the last several years due to new applications for this material. In this work we studied the effect of starting materials and crystal growth methods on the optical and mechanical properties of sapphire, especially concentrating on the effect of hydrogen on the properties of sapphire. It was found that the infrared (IR) absorption which is traditionally used to measure the hydrogen content in sapphire crystals cannot be reliably used and the data obtained by this method provides a much lower hydrogen concentration than actual. We have shown for the first time that Nuclear Magnetic Resonance techniques can be successfully used to determine hydrogen concentration in sapphire crystals. We have shown that hydrogen concentration in sapphire can reach thousands of ppm if these crystals are grown from Verneuil starting material or aluminum oxide powder. Alternatively, the hydrogen concentration is very low if sapphire crystals are grown from High Purity Densified Alumina (HPDA ®) as a starting material. HPDA ® is produced by EMT, Inc through their proprietary patented technology. It was found that optical and mechanical properties of sapphire crystals grown using EMT HPDA ® starting material are much better than those sapphire crystals grown using a starting material of Verneuil crystals or aluminum oxide powder.

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Section: Impurity Measurement Resultssupporting

confidence: 92%

Section: Measurement Techniquesmentioning

confidence: 74%

Hydrogen effect on the properties of sapphire

Mogilevsky

Sharafutdinova

Nedilko

et al. 2009

Window and Dome Technologies and Materials XI

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“…[9] In corundum, aluminum can be replaced by elements, for example, like iron, titanium, chromium or vanadium in the octahedral sites, and these elements cause the particular influence of the spectroscopic properties of corundum. [12][13][14][15][16][17][18][19][20][21][22] No investigation has been done, focusing on the influence of trace element content and the Raman spectra of natural sapphires with different Fe 2 O 3 content.…”

Section: Introductionmentioning

confidence: 99%

The influence of the Fe₂O₃ content on the Raman spectra of sapphires

Phan

Häger

Hofmeister

2016

J Raman Spectroscopy

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In this paper, we study the influence of the Fe2O3 content on the Raman spectra of sapphires by confocal micro Raman spectroscopy and Electron Probe Micro Analysis (EPMA) on a wide variety of sapphire samples collected from 18 different mining regions. Almost all of the samples have a basaltic origin, which is often characterized by a high Fe2O3 content. The Raman peak positions of the two peaks at 418.3 cm−1 and 577.7 cm−1 shift in the investigated area linearly with the Fe2O3 content. This correlation can be applied in, for example, estimating the Fe2O3 content in sapphire or corundum in general and contributes in distinguishing sapphires from different origins. Copyright © 2016 John Wiley & Sons, Ltd.

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“…Infrared spectroscopy may provide additional proof that the gemstone was not heat treated, when AlO(OH) is present, as well as a very good indication of whether it is natural or synthetic (Volynets et al, 1972;Beran, 1991;Smith, 1995, pp. 326-328).…”

Section: DI Is Sc Cu Us Ss Si Io On Nmentioning

confidence: 99%