• Title/Summary/Keyword: Lanthanum

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Development of Lithium Lanthanum Titanate (LLTO) Membrane Manufacturing Process for Selective Separation of Lithium Ion (리튬이온의 선택적 투과를 위한 Lithium Lanthanum Titanate계 분리막 제조 공정 개발)

  • Young Il Kim;Sang Cheol Park;Kwang Ho Shin;InYeong Kim;Kee-Ahn Lee;Sung-Kyun Jung;Bin Lee
    • Journal of Powder Materials
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    • v.30 no.1
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    • pp.22-28
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    • 2023
  • The global demand for raw lithium materials is rapidly increasing, accompanied by the demand for lithiumion batteries for next-generation mobility. The batch-type method, which selectively separates and concentrates lithium from seawater rich in reserves, could be an alternative to mining, which is limited owing to low extraction rates. Therefore, research on selectively separating and concentrating lithium using an electrodialysis technique, which is reported to have a recovery rate 100 times faster than the conventional methods, is actively being conducted. In this study, a lithium ion selective membrane is prepared using lithium lanthanum titanate, an oxide-based solid electrolyte material, to extract lithium from seawater, and a large-area membrane manufacturing process is conducted to extract a large amount of lithium per unit time. Through the developed manufacturing process, a large-area membrane with a diameter of approximately 20 mm and relative density of 96% or more is manufactured. The lithium extraction behavior from seawater is predicted by measuring the ionic conductivity of the membrane through electrochemical analysis.

Synthesis and luminescence properties of lanthanum oxides/hydroxides nanorod bundles

  • Hussain, Sk. Khaja;Raju, G. Seeta Rama;Yu, Jae Su
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.171.2-171.2
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    • 2015
  • Nowadays, trivalent rare-earth ($RE^{3+}$) ions activated metal oxides have been proved to be excellent host materials due to their various applications. Facile wet-chemical technique have been considered as the best synthetic route due its intensive interest in the preparation of nanostructures. Europium ion doped lanthanum hydroxide ($La(OH)_3:Eu^{3+}$) phosphors were synthesized by the facile wet chemical method using the hexamethylenetetramine (HMTA) as a mediated surfactant. The thermal behavior for the $La(OH)_3:Eu^{3+}$ phosphors was investigated by thermogravimetric and differential thermal analysis method. The morphological studies were measured by scanning electron microscope and transmission electron microscope measurements, indicating three-dimensional (3D) flower-like $La(OH)_3:Eu^{3+}$ nanorod bundles. After subsequent annealing process, the lanthanum oxide ($La_2O_3:Eu^{3+}$) phosphor exhibited similar kind of morphology. The synthesized $La(OH)_3:Eu^{3+}$ and $La_2O_3:Eu^{3+}$ samples were characterized by X-ray powder diffraction and Fourier transform infrared spectroscopy. Furthermore, photoluminescence and cathodoluminescence properties were studied in details.

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Growth and characterization of LaxSryMnzO3 nanorod (LaxSryMnzO3 나노로드 성장 및 특성 분석)

  • Kim, Young Jung
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.26 no.2
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    • pp.74-79
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    • 2016
  • The lanthanum oxide nano-rods were grown on the surface of 3 mol% Yttria Partially Stabilized Zirconia ceramic composite which containing Lanthanum-Strontium Manganate, $La_xSr_yMn_zO_3$ for the purpose of endorsing the antistatic property. The diameter and the aspect ratio of the nano-rods were greatly changed according to the growing condition. With the optical microscope observation, the nano-rods shining brightly. It was confirmed that the major components of nano-rods is La, and Sr, Mn, Si are minor components by SEM and TEM analyses.

The effect of lanthanum on the solidification curve and microstructure of Al-Mg alloy during eutectic solidification

  • Xie, Shikun;Yi, Rongxi;Guo, Xiuyan;Pan, Xiaoliang;Xia, Xiang
    • Advances in materials Research
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    • v.4 no.2
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    • pp.77-85
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    • 2015
  • The influence of rare earth lanthanum (La) on solidification cooling range, microstructure of aluminum-magnesium (Al-Mg) alloy and mechanical properties were investigated. Five kinds of Al-Mg alloys with rare earth content of La (i.e., 0, 0.5, 1.0, 1.5 and 2.0 wt.%) were prepared. Samples were either slowly cooled in furnace or water cooled. Results indicate that the addition of the rare earth (RE) La can significantly influence the solidification range, the resultant microstructure, and tensile strength. RE La can extend the alloy solidification range, increase the solidification time, and also greatly improve the flow performance. The addition of La takes a metamorphism effect on Al-Mg alloy, resulting in that the finer the grain is obtained, the rounder the morphology becomes. RE La can significantly increase the mechanical properties for its metamorphism and reinforcement. When the La content is about 1.5 wt.%, the tensile strength of Al-Mg alloy reaches its maximum value of 314 MPa.

Lanthanum Nickelates with a Perovskite Structure as Protective Coatings on Metallic Interconnects for Solid Oxide Fuel Cells

  • Waluyo, Nurhadi S.;Park, Beom-Kyeong;Song, Rak-Hyun;Lee, Seung-Bok;Lim, Tak-Hyoung;Park, Seok-Joo;Lee, Jong-Won
    • Journal of the Korean Ceramic Society
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    • v.52 no.5
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    • pp.344-349
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    • 2015
  • An interconnect is the key component of solid oxide fuel cells that electrically connects unit cells and separates fuel from oxidant in the adjoining cells. To improve their surface stability in high-temperature oxidizing environments, metallic interconnects are usually coated with conductive oxides. In this study, lanthanum nickelates ($LaNiO_3$) with a perovskite structure are synthesized and applied as protective coatings on a metallic interconnect (Crofer 22 APU). The partial substitution of Co, Cu, and Fe for Ni improves electrical conductivity as well as thermal expansion match with the Crofer interconnect. The protective perovskite layers are fabricated on the interconnects by a slurry coating process combined with optimized heat-treatment. The perovskite-coated interconnects show area-specific resistances as low as $16.5-37.5m{\Omega}{\cdot}cm^2$ at $800^{\circ}C$.

Homogeneous Alignment Characteristics of Liquid Crystal Molecules on Solution-Derived Lanthanum Zinc Oxide Film with Ion-Beam Irradiation (이온빔 조사된 용액 공정 기반 LaZnO 박막 위 액정 분자의 수평 배향 특성)

  • Oh, Byeong-Yun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.5
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    • pp.382-386
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    • 2019
  • The alignment characteristics of liquid crystal (LC) molecules on a solution-derived lanthanum zinc oxide (LZO) film under ion-beam irradiation were demonstrated. Using the solution process, an LZO film was fabricated on the glass substrate and cured at $100^{\circ}C$. Afterwards, ion-beam irradiation was performed following the LC alignment method. Using this film, an LC cell was fabricated and the characteristics of the LC alignment were verified. Cross polarizing microscopy and the crystal rotation method were used to investigate the alignment state of the LC molecules on the LZO films. Furthermore, field emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to explore the effect of the ion-beam irradiation on the LZO film. Through these, it was confirmed that the ion-beam irradiation induced surface modification, which demonstrated anisotropic physical and chemical surface characteristics. Due to this, uniform LC alignment was achieved. Finally, the residual DC and anchoring energy of the LC cell based on the LZO films were measured using a capacitance-voltage curve.

Determination of La in $U_3Si/Al$ Spent Nuclear Fuel by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry (Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry에 의한 $U_3Si/Al$ 사용후핵연료 중 La의 분리 및 정량)

  • Han, Sun Ho;Choi, Kwang Soon;Kim, Jung Suk;Jeon, Young Shin;Park, Yang Soon;Jee, Kwang Yong;Kim, Won Ho
    • Analytical Science and Technology
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    • v.13 no.5
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    • pp.601-607
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    • 2000
  • Lanthanum has been used as one of the burnup monitor in spent nuclear fuel. $U_3Si/Al$ spent nuclear fuel contains small amount of La in high concentration of U and Al. Therefore, chemical separation of La is required to remove matrix elements. At first, ion chromatography (IC) and inductively coupled plasma systems were installed in radiation shielded glove box to handle the radioactive samples. Retention behavior of uranium, aluminum, lanthanum and some interesting fission products (Sr, Zr, Y, Mo, Ru, Pd, Rh, Cs, Ba, Ce, Pr, Nd, Sm, Eu and Cd) was investigated using the CG10 column and ${\alpha}$-HiBA eluent. As all elements were eluted earlier than lanthanum in 0.2 M ${\alpha}$-HiBA eluent, a portion of U and Al was directly passed to waste using a three way valve between the column and the nebulizer. Thus it was possible to determine the lanthanum in a high concentration of U and Al matrix. Retention time of La was about 12 minutes in this separation condition. Optimum range for the determination of La in $U_3Si/Al$ spent nuclear fuel was $1-10{\mu}g/L$ (ppb) with this system and detection limit was $0.25{\mu}g/L$ in case of $200{\mu}L$ of sample volume.

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