Yttrium-aluminum garnet

Hardy et al. [204] reported emulsion synthesis of yttrium aluminum garnet (commonly known as YAG) in which yttrium acetate and aluminum secondary butoxide (heated to 85 -90 C) were used as cation sources in a butanol-water mixture. The oil phase was heptane, mineral oil or Isopar, and the surfactant was a mixture of Span 20 (75%) and Span 80 (25%). The sol droplets were gelled by addition of NH4OH or bubbling NH3. The particle morphology and size were influenced significantly by the nature of the oil phase. 

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Neodymium-doped yttrium aluminum garnet laser (NldiYAG)... 

The molecular extinction coefficients (at various wavelengths) of the four main components of the irradiation are shown in Table 5. The absorption of light above 300 nm is favored by tachysterol. A yield of 83% of the previtamin at 95% conversion of 7-dehydrocholesterol can be obtained by irradiation first at 254 nm, followed by reirradiation at 350 nm with a yttrium aluminum garnet (YAG) laser to convert tachysterol to previtamin D. A similar approach with laser irradiation at 248 nm (KrF) and 337 nm (N2) has also been described (76). 

Neodymium-doped yttrium-aluminum garnet is among the most commonly applied laser material and has broad application (neodymium-YAG). 

Silver-colored, ductile metal that is attacked slowly by air and water. The element exhibits interesting magnetic properties. Found in television tubes. Laser material such as YAG (yttrium-aluminum garnet) doped with holmium (as well as chromium and thulium) can be applied in medicine, especially in sensitive eye operations. 

Garnets are important gems, abrasives, microwave systems components, magnetic bubble memories, and laser hosts. For the latter, yttrium aluminum garnet is the most important. It also plays an important role in aircraft turbines where it forms a protective coating on the turbine blades. 

YjAlsOn)—YAG Most garnets are silicates, whereas yttrium aluminum garnet (YAG) is an aluminate. In YAG, both the tetrahedral and the octahedral holes of the garnet structure are occupied by Al-ions and the quasi-cubic holes are occupied by Y-ions. 

Figure 15.1 Comparison of the hot hardnesses of three strong oxides and the strong intermetallic compound, Ni3Al. Yttrium aluminum garnet is the hardest of all oxides at high temperatures.

Fig. 7 Creep-resistance of the eutectic fiber consisting of interpenetrating phases of alpha-alumina and yttrium-aluminum-garnet (YAG) up to very high temperatures compared with other types of oxide fibers... 

Solid-state lasers using substitutional neodymium (Nd3+ ions) as the active defects are widely available. Practical lasers contain about 1% Nd3+ dopant. The most common host materials are glass, yttrium aluminum garnet (YAG), Y3A15012, and calcium tungstate, CaW04. In the crystalline host structures, the defects responsible for amplification are NdY and Ndca-... 

Yttrium(Y), 14 644, 645 Yttrium aluminosilicate (YAS) glass microspheres, 12 612 Yttrium aluminum garnet (YAG), 19 411 color, 7 331... 

Figure 8.7. Delayed fluorescence and diffuse reflectance transient absorption spectroscopy on scattering substrates. Example terthicnyl on silica gel excited with = 354 nm (neodymium/yttrium-aluminum-garnet) (Nd/YAG) laser pulse of 10 nsec, 20 mj), recorded with a gated diode array spectrometer.

Some rare-earth-activated materials do show strong fluorescence phenomena at temperatures even up to IOOO°C with a lifetime long enough to be detected without particular difficulties, as demonstrated in the cases of neodymium yttrium-aluminum-garnet(Nd YAG) andScPC>4 Eu3+ by Grattan etal.m and Bugos etal.,m respectively. 

K. T. V. Grattan, J. D. Manwell, S. M. L. Sim, and G A. Willson, Lifetime investigation of fluorescence from neodymium-yttrium-aluminum garnet at elevated-temperature. Optics Commun. 62(2), 104-107 (1987). 

The yttrium aluminum garnet crystal, Y3 AI5O12, doped withNd + ions, is a well-known solid state laser material (abbreviated to Nd YAG). If the fluorescence lifetime of the main laser emission is 230 /rs and the quantum efficiency of the corresponding emitting level is 0.9, determine (a) the radiative lifetime and... 

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