• Geosciences Journal
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• v.22 no.6
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• pp.939-953
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• 2018

We examined the microfabrics of omphacite and garnet in foliated eclogite to determine the influence of the layered structure on seismic observations in subduction zone. The analyzed eclogite, from the Lanterman Range, northern Victoria Land, Antarctica, is characterized by layering in which the modal abundances of garnet and omphacite vary. For garnet, the low aspect ratios, similar angular distribution of long axes relative to the foliation in both layers, uniform grain size distribution, near-random crystallographic preferred orientations (CPOs), and misorientation angle distributions are indicative of passive behavior during deformation. In contrast, omphacite shows relatively high aspect ratios, a low angle between the long axes of crystals and the foliation, a wide grain-size distribution, and distinctive CPOs, suggesting dislocation creep as the main deformation mechanism. The results of fabric analyses are consistent with strain localization into omphacite or omphacite-rich layers rather than garnet or garnet-rich layers. The single-crystal seismic anisotropy of garnet is very weak ($AV_P=0.2%$, $AV_S=0.5-0.6%$), whereas that of omphacite is much stronger ($AV_P=3.7-5.9%$ and $AV_S=2.9-3.8%$). Seismic anisotropy of the omphacite-rich layers shows an increase of 329% for $AV_P$ and 146% for $AV_S$ relative to the garnet-rich layers. Our results demonstrate the importance of the layered structure in strain localization and in the development of the seismic anisotropies of subducting oceanic crust.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.231.1-231.1
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• 2008

• Journal of the Korean Magnetics Society
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• v.8 no.6
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• pp.350-356
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• 1998

$Y_{3-x}La_xFe_5O_{12}$ (x=0.0, 0.25, 0.5, 0.75, 1.0) powders and thin films were fabricated by a sol-gel method and their magnetic properties and crystal structure were investigated by using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and Mossbauer spectroscopy. XRD and Mossbauer spectroscopy measurements show that garnet powders annealed at 900 $^{\circ}C$ for 8 hours were single-phased and that thin films fired at 800 $^{\circ}C$ for 2 hours were crystallized without any preferred direction. X-ray diffraction patterns of $Y_{3-x}La_xFe_5O_{12}$ powders annealed at 1000 $^{\circ}C$ had only peaks of the garnet structure in case of x$\leq$0.75 but those of $Y_2LaFe_5O_{12}$ powders consisted of peaks from garnets and $LaFeO_3$. Mossbauer sepectra of garnet powders grown by the sol-gel method had a similar shape of those of powders grown by a conventional ceramic method. Grain sizes of garnet powders were 200~300 nm and the averaged surface roughness was 3.17 nm. Results of VSM measurements show the powders and thin films had soft magnetic properties and that the garnet powders had the largest saturation magnetization, 30 emu/g, and the lowest coercivity, 52 Oe.

• Journal of the Korean Ceramic Society
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• v.54 no.4
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• pp.278-284
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• 2017

In this work, Ta-substituted $Li_7La_3Zr_{2-x}O_{12}$ (LLZTO) powder and pellets with garnet cubic structure were fabricated and characterized by modified and optimized sol-gel synthesis. Ta-substituted LLZO powder with the smallest grain size and pure cubic structure with little pyrochlore phase was obtained by synthesis method in which Li and La sources in propanol solvent were mixed together with Zr and Ta sources in 2-methoxy ethanol. The LLZTO pellets made with the prepared powder showed cubic garnet structure for all conditions when the amount of Li addition was varied from 6.2 to 7.4 mol. All the X-ray peaks of the pyrochlore phase disappeared when the Li addition was increased above 7.0 mol. When the final sintering temperature was varied, the LLZTO pellet had a pyrochlore-mixed cubic phase above $1000^{\circ}C$. However, the surface morphology became much denser when the final sintering temperature was increased. The sol-gel-driven LLZTO pellet with a sintering temperature of $1100^{\circ}C$ showed a lithium ionic conductivity of 0.21 mS/cm when Au was adopted as electrode material for the blocking capacitor. The results of this study suggest that modified sol-gel synthesis is the optimum method to obtain cubic phase of LLZTO powder for highly dense and conductive solid electrolyte ceramics.

• Medical Lasers
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• v.9 no.2
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• pp.184-186
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• 2020

Lower eyelid blepharoplasty is a popular facial rejuvenation surgery that restores the infraorbital region. The procedure is performed by removing excessive fatty tissues, muscles, and other unnecessary structures. The structure of the eyelid differs from person to person and is quite complex; therefore, numerous side effects are expected. Common lower eyelid blepharoplasty complications are asymmetrical faces, retrobulbar hemorrhage, blurred vision, and ectropion. This paper reports a case of a prominent periorbital vein after lower eyelid blepharoplasty. The prominent periorbital vein after surgery is a rare side effect that has not been reported to the best of the author's knowledge. This case was treated with a long-pulse 1,064-nm neodymium:yttrium-aluminum-garnet laser.

• Corrosion Science and Technology
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• v.4 no.1
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• pp.33-38
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• 2005

Some feasibility studies are conducted to produce an advanced ceramic coating, which reveals superior chemical and mechanical strength, on metal base structure used in chemical plant. This advanced coating on metallic frame can replace ceramic delivery pipe and reaction chamber used in chemical plant, which are operated in hi-temperature and corrosive/erosive environment. An dual spraying is adopted to reduce the residual stress in order to increase the coating thickness and the residual stress is estimated by in-situ manner. Then new methodology is tried to form special coating of yttrium aluminum garnet(YAG), which reveals hi-strength and low-creep rates at hi-temperature, superior anti-corrosion property, hi-stability against Alkali-Vapor corrosion, and so on, on iron base structure. To verify the formation of YAG during thermal spraying, XRD(X ray diffraction) technique was used.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.720-725
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• 1995

Bi-substituted gadolinium iron garnet films were deposited on GGG(111) and NGG (111) substrates by irradiating KrF excimer laser onto targets having compositions of $Bi_{x}Gd_{3-x}Fe_{5}O_{12}$ ($2.0{\leq}x{\leq}3.0$) under substrate temperature of $580~620^{\circ}C$. Analysis on structure, composition and angle of Faraday rotation, ${\theta}_{F}$, were carried out. The composition, the structure and the magneto-optical properties of the obtained films were found to be strongly dependent both on the compositions of the targets and on the pressure of oxygen. Before annealing in air, all films showed ${\theta}_{F}{\geq}0$ at ${\lambda}=6328{\AA}$, while several films showed ${\theta}_{F}{\leq}0$ after the annealing. The highest value of Bi-substitution up to x = 1.76 with uniform composition was obtained.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2917-2921
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• 2014

Cerium-activated yttrium aluminate ($Y_3Al_5O_{12}:Ce^{3+}$) exhibiting a garnet structure has been widely utilized in the production of light emitting diodes (LEDs) as a yellow emitting phosphor. The commercialized yttrium aluminum garnet (YAG) phosphor is typically synthesized by a solid-state reaction, which produces irregular shape particles with a size of several tens of micrometers by using the top-down method. To control the shape and size of particles, which had been the primary disadvantage of top-down synthetic methods, we synthesized YAG:Ce nanoparticles with a diameter of 500 nm using a coprecipitation method under the atmospheric pressure without the use of template or special equipment. The precursor particles were formed by refluxing an aqueous solution of the nitrate salts of Y, Al, and Ce, urea, and polyvinylpyrrolidone (55 K) at $100^{\circ}C$ for 12 h. YAG:Ce nanoparticles were formed by the calcination of precursor particles at $1100^{\circ}C$ for 10 h under atmospheric conditions. The phase identification, microstructure, and photoluminescent properties of the products were evaluated by X-ray powder diffraction, scanning electron microscopy, absorption spectrum and photoluminescence analyses.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.6
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• pp.536-540
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• 2007

The Ce-doped YAG(Yttrium Aluminum Garnet, $Y_3Al_5O_{12}$) phosphor powders were synthesized by combustion method. The luminescence, formation process and structure of phosphor powders were investigated by means of XRD, SEM and PL. The XRD patterns show that YAG Phase can form through sintering at $1000^{\circ}C$ for 2 h. This temperature is much lower than that required to synthesize YAG phase via the conventional solid state reaction method. There were no intermediate Phases such as YAP(Yttrium Aluminum Perovskite, $YAlO_3$) and YAM(Yttrium Aluminum Monoclinic, $Y_4Al_2sO_9$) observed in the sintering process. The powders absorbed excitation energy in the range $410{\sim}510\;nm$. Also, the crystalline YAG:Ce showed broad emission peaks in the range $480{\sim}600\;nm$ and had maximum intensity at 528 nm.

• Journal of Magnetics
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• v.12 no.3
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• pp.129-132
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• 2007

Bismuth-substituted yttrium iron garnet (Bi:YIG, $Bi_{0.5}Y_{2.5}Fe_5O_{12}$) films were deposited with aerosol deposition method and their magnetic and optical properties were investigated as a function of annealing temperature. Since the ceramic films deposited with aerosol deposition method have not a perfect crystal structure due to non-uniform internal stress occurred by mechanical collision during their deposition, the post annealing could be a key process to release its internal stress and to improve its micro structure for optimizing the magnetic and magneto-optic properties of films. The crystallinity of Bi: YIG film was improved with increase of annealing temperature, and the saturation magnetization increased up to 87 emu/cc at $800^{\circ}C$. The Faraday rotation increased up to $1.4deg/{\mu}m$ by annealing at $700^{\circ}C$ around the wavelength of $0.5{\mu}m$. The optical transmittance of the Bi:YIG film was also improved in visible region.