• 제목/요약/키워드: Garnet

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Effect of Al and Nb Doping on the Electrochemical Characteristics of Garnet-type Li7La3Zr2O12 Solid Electrolytes

  • Ahmed Tarif;Chan-Jin Park
    • Corrosion Science and Technology
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    • 제22권6호
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    • pp.408-418
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    • 2023
  • In this study, we synthesized and characterized garnet-type Li7-xAlxLa3Zr2-(5/4)yNbyO12 (LALZN) solid electrolytes for all-solid-state battery applications. Our novel approach focused on enhancing ionic conductivity, which is crucial for battery efficiency. A systematic examination found that co-doping with Al and Nb significantly improved this conductivity. Al3+ and Nb5+ ions were incorporated at Li+ and Zr4+ sites, respectively. This doping resulted in LALZN electrolytes with optimized properties, most notably enhanced ionic conductivity. An optimized mixture with 0.25 mol each of Al and Nb dopants achieved a peak conductivity of 1.32 × 10-4 S cm-1. We fabricated symmetric cells using these electrolytes and observed excellent charge-discharge profiles and remarkable cycling longevity, demonstrating the potential for long-term application in battery systems. The garnet-type LALZN solid electrolytes, with their high ionic conductivity and stability, show great potential for enhancing the performance of all-solid-state batteries. This study not only advances the understanding of effective doping strategies but also underscores the practical applicability of the LALZN system in modern energy storage solutions.

신예미(新禮美) 연(鉛)-아연광상산(亞鉛鑛床産) 스카른광물(鑛物)의 광물학적(鑛物學的) 연구(硏究) (A Mineralogical Study of the Skarn Minerals from the Shinyemi Lead-Zinc Ore Deposits, Korea)

  • 김규한;나카이 노부유키;김옥준
    • 자원환경지질
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    • 제14권4호
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    • pp.167-182
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    • 1981
  • 신예미광상(新禮美鑛床)의 스카른 광물(鑛物)은 1) 석류석(石榴石)-휘석(輝石)-금운모(金雲母)-규회석(硅灰石) 조합(組合)군집, 2) 석류석(石榴石)-휘석(輝石) 조합(組合), 3)석류석(石榴石)-녹렴석(綠廉石) 조합(組合)으로 구분(區分)된다. 이들 광물조합(鑛物組合)은 광석광물(鑛石鑛物)의 산출상태, 광석광물(鑛石鑛物)의 종류(種類) 그리고 광화작용(鑛化作用)의 시기(時期)와 밀접한 관계(關係)가 있다. 석류석결정(石榴石結晶)의 분석(分析)에 의하여 석류석결정(石榴石結晶)의 누대구조(累帶構造)는 결정(結晶)의 성장시(成長時)에 평형조건(平衡條件)의 변화(變化)에 기인한 화학적(化學的) 누대구조(累帶構造)(chemical compositional zoning) 이다. 그리고 광상(鑛床)의 생성환경(生成環境)과 관계화성암(關係火成岩)의 위치(位置)를 스카른광물(鑛物)의 산출상태와 스카른 광물중(鑛物中) 석류석(石榴石)의 화학성분(化學成分)의 검토에 의해 추정해 보았다.

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Microshear bond strength according to dentin cleansing methods before recementation

  • Tasar, Simge;Ulusoy, Mutahhar Muhammed;Meric, Gokce
    • The Journal of Advanced Prosthodontics
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    • 제6권2호
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    • pp.79-87
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    • 2014
  • PURPOSE. The aim of this study was to determine the efficiency of Erbium, Chromium: Yttrium-Scandium-Gallium-Garnet laser in different output powers for removing permanent resin cement residues and therefore its influence on microshear bond strength compared to other cleaning methods. MATERIALS AND METHODS. 90 extracted human molars were sectioned in 1 mm thickness. Resin cement was applied to surface of sliced teeth. After the removal of initial cement, 6 test groups were prepared by various dentin surface treatment methods as follows: no treatment (Group 1), ethylene diamine tetra acetic acid application (Group 2), Endosolv R application (Group 3), 1.25 W Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet laser irradiation (Group 4), 2 W Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet laser irradiation (Group 5) and 3.5 W Erbium, Chromium:Yttrium-Scandium-Gallium-Garnet laser irradiation (Group 6). The topography and morphology of the treated dentin surfaces were investigated by scanning electron microscopy (n=2 for each group). Following the repetitive cementation, microshear bond strength between dentin and cement (n=26 in per group) were measured with universal testing machine and the data were analyzed by Kruskal Wallis H Test with Bonferroni correction (P<.05). Fracture patterns were investigated by light microscope. RESULTS. Mean microshear bond strength ${\pm}$ SD (MPa) for each group was $34.9{\pm}17.7$, $32.1{\pm}15.8$, $37.8{\pm}19.3$, $31.3{\pm}12.7$, $44.4{\pm}13.6$, $40.2{\pm}13.2$ respectively. Group 5 showed significantly difference from Group 1, Group 2 and Group 4. Also, Group 6 was found statistically different from Group 4. CONCLUSION. 2 W and 3.5 W Erbium, Chromium: Yttrium-Scandium-Gallium-Garnet laser application were found efficient in removing resin residues.

Al-Fe Partitioning between Coexisting Garnet and Epidote from Metamorphic Rocks

  • Kim, Hyung-Shik;Kim, Young-Kyum;Jang, Young-Nam
    • 암석학회지
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    • 제2권2호
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    • pp.63-73
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    • 1993
  • The assemblage epidote and grandite garnet occurs in low-to medium-grade metabasites and calc schists of various geotectonic settings and in hydrothermally altered calcareous rocks in skarn deposits. The compositions of sixteen epidote-garnet paris have been analysed by means of electron microprobe. Al-Fe partitioning between coexisting grandite garnet and epidote is considered and measured at the grain boundaries on the supposition that the surface equilibrium was maintained in the following exchange reaction: 2$Ca_2Al_3Si_3O_12$(OH)+$Ca_3Fe_2Si_3O_12$=2$Ca_2A_l2FeSi_3O_12$(OH)+$Ca_3Al_2Si_3O_12$ Partition coefficients confirms the differences in thermal conditions between low-grade and medium-grade metamorphic rocks. $K_D$ values ($X_{$CO_2$}$=($Fe^{+3}$/Al)$^{Ep}$/($Fe^{+3}$/Al)$^{Gr}$, where Fe=$Fe^{+3}$) from greenschist facies rocks of the estimated metamorphic temperatures, 330~$390^{\circ}C$, range approximately between 0.02 and 0.17. Epidote-amphibolite facies rocks and calcareous skarns of the estimated temperatures, 400~$550^{\circ}C$, have $K_D$ values between 0.24 and 0.37. $K_D$ values from the rocks of the temperatures, 640~$700^{\circ}C$, range nearly between 0.58 and 0.75. The diagrams in Figs. 2 and 3 can serve as a mineralogic thermometer for relatively shallow rocks, assuming that the pressure dependence of partition coefficients for the iron-exchange reaction in the two minerals can be neglected.

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재활용 천연광물 연마재의 연마성능 (Ability of the Natural Abrasives Recovered from Sludge)

  • 조성백;서명덕;조건준;이수정
    • 한국광물학회지
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    • 제22권4호
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    • pp.353-358
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    • 2009
  • CRT 브라운관 패널의 연마과정에서 배출되는 폐연마슬러지로부터 석류석 등의 연마재를 회수하고, 연마성능을 평가하였다. 재활용 부석과 석류석으로 연마한 유리의 평균표면거칠기값(Ra = $0.025{\mu}m$, = $0.029{\mu}m$)은 새 연마재로 연마한 유리에서의 값(Ra = $0.039{\mu}m$, $0.031{\mu}m$)보다 작았으며 표면의 선이나 홈도 적었다. 루즈의 경우 유리 파편이 혼입되어 연마재로 재활용하기에는 적합하지 않다. 본 기술을 이용하여 폐연마슬러지에 함유된 천연연마재 광물자원인 부석과 석류석을 회수한다면 CRT 유리 연마공정에서 재활용할 수 있고, 슬러지 매립으로 발생되는 처리비용과 환경오염문제를 줄일 수 있을 것이다.

Structural and Magnetic Properties of (CoFe2O4)0.5(Y3Fe5O12)0.5 Powder

  • Lee, Jae-Gwang;Chae, Kwang-Pyo;Lee, Young-Bae;Lee, Sung-Ho
    • Journal of Magnetics
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    • 제10권3호
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    • pp.80-83
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    • 2005
  • Cobalt ferrite and garnet powders were grown using a conventional ceramic method in two different ways for understanding the magnetic interaction between structurally different materials. Structures of these powders were investigated by using an X-ray diffractometer (XRD) and the magnetic interaction between iron ions and the magnetic properties of the powders were measured by a $M\ddot{o}ssbauer$ spectroscopy and a vibrating sample magnetometer (VSM), respectively. The result of the XRD measurement showed that the annealing temperature higher than $1200^{\circ}C$ was necessary to grow a $(CoFe_2O_4)_{0.5}(Y_3Fe_5O_{12})_{0.5}$ powder. $M\ddot{o}ssbauer$ spectra for the powders grown separately and mixed mechanically consisted of sub-spectra of cobalt ferrite and garnet, however, powders annealed together had an extra sub-spectrum, which was related with the magnetic interaction between the grain surface of cobalt ferrite and the one of the garnet. In case of annealing the powders at the temperature large enough to crystallize them, raw chemicals became fine cobalt ferrite and garnet particles at first and then these fine particles were aggregated and formed large grains of ferrite powders. The result of the VSM measurement showed that the powders prepared at $1200^{\circ}C$ had the similar saturation magnetization and the coercivity regardless of the preparation method.

산업부산물인 가네트 미분말을 이용한 고강도 콘크리트의 실용화에 관한 실험 연구 (An Experimental Study on the Practical Application of High Strength Concrete using Garnet Powder with industrial by-products)

  • 윤명덕;김상헌;임병호;김태곤;박정민;김화중
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.439-444
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    • 2000
  • The purpose of this study is to investigate the possibility of Garnet powder as admixture of high strength concrete. The experiment condition is unit water content 160kg/㎥, W/B=30, 35%, S/A=40, 42, 44% and the cement was replaced with Garnet powder to 0, 10% of cement weight on making specimens. The mechanical properties of the fresh and hardened concrete were given as follows. As the time elapsed, the slump loss of 10% replaced concrete was considerably lower than that of 0% replaced concrete. In compressive strength, the 10% replacement case was nearly the same or somewhat high.

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균일침전법에 의한 Yttrium Iron Garnet 분말의 합성 및 결정화 (Synthesis of Yttrium Iron Garnet Powder by Homogeneous Precipitation and its Crystallization)

  • 안영수;한문희;김종오
    • 한국세라믹학회지
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    • 제33권6호
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    • pp.693-699
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    • 1996
  • YIG precursor powder was obtained by homogeneous precipitation in chloride salt solution by thermal decom-position of urea. It was found that ferric ions precipitated prior to yttrium ions. The precipitate was minute and spherical in shape. The precipitate formed consisted of the mixture of amorphous and ferric oxyhydroxide. Crystallization of YIG was proceeded by solid state reaction of intermediate YFeO3 and Fe2O3 in the temperature range of 85$0^{\circ}C$ to 140$0^{\circ}C$. Single phase of YIG was obtained by heat-treatment of the powder at 140$0^{\circ}C$ for 6 hrs in air. The powder calcined was molded into pellets and sintered in air. The maximum density of 4,92 g/cm3(95.1% of theoretical density) was obtainable for the pellet sintered at 145$0^{\circ}C$ using the powder calcined at 90$0^{\circ}C$.

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Paleoproterozoic low-pressure metamorphism and crustal evolution in the northeastern Yeongnam Massif, Korea

  • Kim, Jeong-Min
    • 한국암석학회:학술대회논문집
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    • 한국암석학회 2006년도 동계학술심포지엄
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    • pp.43-60
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    • 2006
  • The Yeongnam Massif, one of Precambrian basements in Korean Peninsula, is characterized by widespread occurrence of low-pressure/high-temperature (LP/HT) schists and gneisses accompanying extensive anatexis and granitic magmatism. Metapelitic mineral assemblages define three progressive metamorphic zones pertinent to low-pressure facies series: cordierite, sillimanite and garnet zones with increasing temperature. Metamorphic grade ranges from lower amphibolite to lower granulite facies and metamorphic conditions reach ca. 750-800 C and 4-6 kbar in migmatitic gneisses. Migmatitic gneisses are prominent in the sillimanite and garnet zones. Textural and petrogenetic relationshipsin leucosome suggest that migmatitic gneiss is the product of anatexis of metasedimentary rocks. The migmatite formation during the prograde metamorphism is governed initially by fluid-present melting and subsequently by biotite-dehydration melting. The large amount of leucosomes in the sillimaniteand garnet zones can be explained by the fluid-present molting possibly triggered by an external supply of aqueous fluid. Field and geochronologic relationships between leucogranites and migmatitic gneisses further suggest that leucogranite has providedfluid and heat required for widespread migmatization.

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자기 가넷 박막 동적 특성의 컴퓨터 시뮬레이션에 관한 연구 (A study on the computer simulation of dynamic properties of Magnetic Garnet Thin Films)

  • 김길상;이윤석;최연봉;한은실;오민석;조순철
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1988년도 추계학술대회 논문집
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    • pp.47-49
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    • 1988
  • This paper discusses dynamic properties of bubble garnet thin films. The dynamic properties considered are Gilbert damping parameters, saturation velocity, and wall mobility. The parameters are evaluated to facilitate the search for desirable garnet thin film compositions. Given bubble diameter and Q-value, the computer prints out all compositions which meet the desired requirements. The computer model determines magnetization, anisotropy, damping, velocity, mobility among others from the film compositions. The computer modeling program is described by an algorithm detailing its operation.

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