Methods for Obtaining Complex Monolithic Sapphire Units and Large-Size Crystals

Dobrovinskaya, Elena R.; Lytvynov, Leonid A.; Pishchik, Valerian

doi:10.1007/978-0-387-85695-7_8

Cited by 4 publications

(10 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The crystals have been annealed in strongly reducing conditions (redox potential À230 kJ/mol) that favors conversion of Ti into its 3 þ valence state. 6 It is important to stress that the samples have been produced in the same conditions, providing the necessary benchmark for the comparison and interpretation of the results. The nominal concentrations of Ti in the samples, specified by the manufacturer, were 10, 50, 100, 500, and 1000 ppm.…”

Section: Methodsmentioning

confidence: 99%

Studies of concentration dependences in the luminescence of Ti-doped Al2O3

Mikhailik

Stefano

Henry

et al. 2011

Journal of Applied Physics

View full text Add to dashboard Cite

The variation of luminescence and excitation spectra of titanium doped Al 2 O 3 for the concentration of Ti ranging from 10 to 1000 ppm was investigated using synchrotron radiation. In the lightly doped Al 2 O 3 -Ti (<100 ppm) samples we identified several emission bands. These are the emission of the excitons localized at Ti (290 nm), the emission due to F þ centers (325 nm), the band around 420 nm traditionally attributed to F center emission, and the luminescence of Ti 3þ ions at 720 nm. The emphasis in this study is on the clarification of the nature of the blue emission band in the samples with high concentration of Ti (!100 ppm), where the luminescence and excitation spectra of the blue emission exhibit noticeable variability. This is explained by a model of the luminescence process of Ti 4þ -F centers that includes the photoionization of Ti 3þ , the subsequent capture of electrons at F þ -centers, formation of excited F-centers and, finally, the emission of a blue photon. The quenching of the blue emission with increasing Ti concentration is interpreted in terms of competition between oxygen vacancies and Ti 4þ centers in the capture of the electron.

show abstract

Section: Methodsmentioning

confidence: 99%

Studies of concentration dependences in the luminescence of Ti-doped Al2O3

Mikhailik

Stefano

Henry

et al. 2011

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…However sapphire crystals received by different methods have different technical characteristics which are necessary for application in microelectronics [4,5]. The sapphire crystals growth by horizontally directed crystallization is one of the promising methods.…”

Section: Introductionmentioning

confidence: 99%

Physical and Technological Fundamentals of Sapphire Substrates Production for Devices of Solid-state Electronics

Klunnikova¹,

Malyukov²

2018

KEG

View full text Add to dashboard Cite

The results of numerical simulation allow to investigate the thermal conditions received by active heaters influence on the thermoelastic stresses and gas inclusions in sapphire. We carried out the experiments for defects detection in sapphire crystals. We suggest the recommendations about sapphire crystals growth and processing improvement for profitability increase in sapphire substrates production for microelectronics.

show abstract

“…As one of the most important applications of sapphire crystals, sapphire optical windows have been widely used in different devices operating on ground, under water, or in outer space over a wide range of pressures and temperatures 1 . With the fast development of optical devices in recent years, it is expected to increase the window's size from several millimeters to several hundreds of millimeters and fabricate complex sapphire windows very soon 2 . However, none of the current single crystal growth technologies can be used to grow sapphire crystals beyond 350 mm in diameter, 3 let alone complex sapphire pieces.…”

Section: Introductionmentioning

confidence: 99%

“…In the literature, diffusion welding has been considered to be the most efficient method for joining sapphire crystals 2 . This method has been developed into two kinds of techniques, with 4–10 or without an interlayer 11,12 .…”

Section: Introductionmentioning

confidence: 99%

“…This method has been developed into two kinds of techniques, with 4–10 or without an interlayer 11,12 . Comparing with the latter, an interlayer can firstly melt and then provide a transient liquid phase 7,8,13 or a partial transient liquid phase 5,6,9,10 to assist the spreading and wetting of initial substances, and hence can diminish the temperature, pressure and duration of joining, 14 prevent plastic deformation, relieve residual stresses, and decrease inhomogeneity in the bonding layer 2 . Many metallic interlayer systems such as Cu/Nb/Cu, 10,15 Ni/Nb/Ni, 16,17 Nb/V, 18 Cu, 19,20 Cu/Nb, 21 Cu/Pt/Cu, 5 Cu/Ni/Cu, 6 Cu/Cu 2 O, 22 Cu/Ag, 23 Cu/Al, 24 and Cu/Ti 24 have been invented to join sapphire crystal or alumina.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bonding Layer Microstructures and Mechanical Behavior of Sapphire/Sapphire Joints Diffusion-bonded using MgO-Al2O3-SiO2 Interlayer

Zhang

Xing

Sun

et al. 2011

International Journal of Applied Ceramic Technology

View full text Add to dashboard Cite

The bonding layer microstructures and their effects on fracture behaviors of sapphire joined using MgO (0.5%)–Al2O3 (94%)–SiO2 (5.5%) interlayer are analyzed. The results indicate that the bonding layer is composed by facetted Al2O3 grains and pores and they are controlled by joining conditions. The fracture mode is mainly intergranular for the pieces with fine grains and changes into cleavage fracture as the grain size increases. Optimal microstructures can be obtained under the condition of 1700°C, holding time of 1.5 h and pressure of 3 Mpa and the flexure strength corresponding plane bonded pieces may be beyond 250 MPa and plane bonded pieces may reach above 300 MPa.

show abstract

Methods for Obtaining Complex Monolithic Sapphire Units and Large-Size Crystals

Cited by 4 publications

References 8 publications

Studies of concentration dependences in the luminescence of Ti-doped Al2O3

Studies of concentration dependences in the luminescence of Ti-doped Al2O3

Physical and Technological Fundamentals of Sapphire Substrates Production for Devices of Solid-state Electronics

Bonding Layer Microstructures and Mechanical Behavior of Sapphire/Sapphire Joints Diffusion-bonded using MgO-Al2O3-SiO2 Interlayer

Contact Info

Product

Resources

About