• Korean Journal of Materials Research
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• v.7 no.3
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• pp.180-187
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• 1997

$La_{0.68}Ca_{0.32}Cr_{0.97}O_{3}$ interconnector films ior pimar rypn solid oxide fuel (,ells were prepared under various sinteririg conditions and their bending strength. relative ilerisit~. m t l c:lec ~ ~ - i i ; i l condl~cti\.lt\ were niexiureti in order to study their mechanical and electrical propertics Th' Irndirig sriength of $La_{0.68}Ca_{0.32}Cr_{0.97}O_{3}$ lt the room temperature \vas increased with increasing sinrering temperature dnfl tinic. The relative densit\- of more than 94% was ohtained 1)). sintering at $1400^{\circ}C$ for 5hrs. The present irlvestigiition rovcals thcit sirileririg of $La_{0.68}Ca_{0.32}Cr_{0.97}O_{3}$ at lorn. temperature xyvas greatly assisted by formation oi Ca,,,(CrO,),, Also the i,leitriczl conductivity at $1000^{\circ}C$ \vas more than 100S; cm d t e r heating at $1400^{\circ}C$ for 7hrs.

• Journal of the Korean Chemical Society
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• v.25 no.2
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• pp.61-66
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• 1981

A method for calculation of the contribution of $\pi$ bonding molecular orbitals to the dipole moments for octahedral [M(III)$A_3B_3$] type complexes has been developed [M(III) = Ti(III), V(III), Cr(III), Fe(III) or Co(III); A = O or N; B = N, S or Cl]. The contribution of ${\pi}$ bonding molecular orbitals to the dipole moments is found to be smaller than that of ${\sigma}$ bonding molecular orbitals but this contribution may not be negligible even for chelate complexes in which delocalization of ${\pi}$ electron is assumed. The calculated dipole moments (u = $u_{\sigma}$ + $u_{\pi}$) are closer to the experimental values than those for the case where only ${\sigma}$ bonds are assumed to be formed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.6
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• pp.235-239
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• 2011

TiCrN layers (Ti : Cr = 20 : 80 and 5 : 95 wt%) were deposited on Inconel 617 and the effect of TiCrN coating on the high temperature stability of Inconel 617 up to $1000^{\circ}C$ was examined. XRD analysis and microstructural observation showed that vigorous and inhomogenous Cr diffusion to the surface was suppressed by TiCrN layer compare to the uncoated Inconel 617. This led to a distinctive enhancement in thermal oxidation resistance of Inconel 617.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.11a
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• pp.40-40
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• 2007

• Transactions on Electrical and Electronic Materials
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• v.16 no.5
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• pp.264-267
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• 2015

AlCrNO cermet films were prepared on aluminum substrates using a DC-reactive magnetron sputtering method and a water-cooled Al:Cr target. The Al₂O₃/AlCrNO (LMVF)/AlCrNO (MMVF)/AlCrNO (HMVF)/Al/substrate of the 5 multi-layers was prepared according to the Ar and (N₂ + O₂) gas-mixture rates. The Al₂O₃ of the top layer is the anti-reflection layer of triple AlCrNO (LMVF)/AlCrNO (MMVF)/AlCrNO (HMVF) layers, and an Al metal forms the infrared reflection layer. In this study, the crystallinity and surface properties of the AlCrNO thin films were estimated using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM), while the composition of the thin films was systematically investigated using Auger electron spectroscopy (AES). The optical properties of the wavelength spectrum were recorded using UH4150 spectrophotometry (UV-Vis-NIR) at a range of 0.3 μm to 2.5 μm.

• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.436-441
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• 2001

The emission and excitation spectra of mer-[Cr(dien)(glygly)]ClO$_4$(glygly=glycylglycinate;dien=N-(2-aminoethyl)-1,2-ethanediamine) taken at 77 K are reported. The infrared and visible spectra at 298 K are also measured. The twelve electronic bands due to spin-allowed and spin-forbidden transitions are assigned. Using the observed transitions, a ligand field analysis has been performed to determine the bonding property of coordinated atoms in the chromium(III) complex. It is confirmed that the amine nitrogen atoms of the dien and glygly have strong $\sigma$-donor characters, but the peptide nitrogen of glygly has weak $\pi$-donor property toward chromium(III) ion.

• Journal of the Korean Ceramic Society
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• v.40 no.2
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• pp.139-145
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• 2003

We studied oxidation behaviors of anti-oxidative Y-Cr oxide coated sol on ferritic steel for application of the Fe-Cr alloys as interconnectors of planar-type Solid Oxide Fuel Cells(SOFCs). In coated$YCrO_3$on the ferritic steel, the phases of $YCrO_3$,$Cr_2O_3$and $Mn_{1.5}Cr_{1.5}O_4$on the coated surface were detected, but iron base scales were not observed after oxidation at 80$0^{\circ}C$ for 40 h. The Mn-Cr oxide scales were grown with oxidation by diffusing components in the ferritic steel from inner. The Log(ASR/T) value that expresses electrical resistance of coated$YCrO_3$on the ferritic steel was -4.57~$-4.70{omega}cm^2K^{-1}$, lower in comparison with the one of the uncoated ferritic steel,$-3.99{omega}cm^2K^{-1}$. This indicates the applicability of Fe-l6Cr alloy as interconnector materials for SOFCs.

• The korean journal of orthodontics
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• v.51 no.4
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• pp.270-281
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• 2021

Objective: The aim of this in vitro study was to evaluate the changes in friction between orthodontic brackets and archwires coated with aluminum oxide (Al₂O₃), titanium nitride (TiN), or chromium nitride (CrN). In addition, the resistance of the coatings to intraoral conditions was evaluated. Methods: Stainless steel canine brackets, 0.016-inch round nickel-titanium archwires, and 0.019 × 0.025-inch stainless steel archwires were coated with Al₂O₃, TiN, and CrN using radio frequency magnetron sputtering. The coated materials were examined using scanning electron microscopy, an X-ray diffractometer, atomic force microscopy, and surface profilometry. In addition, the samples were subjected to thermal cycling and in vitro brushing tests, and the effects of the simulated intraoral conditions on the coating structure were evaluated. Results: Coating of the metal bracket as well as nickel-titanium archwire with Al₂O₃ reduced the coefficients of friction (CoFs) for the bracket-archwire combination (p < 0.01). When the bracket and stainless steel archwire were coated with Al₂O₃ and TiN, the CoFs were significantly lower (0.207 and 0.372, respectively) than that recorded when this bracket-archwire combination was left uncoated (0.552; p < 0.01). The friction, thermal, and brushing tests did not deteriorate the overall quality of the Al₂O₃ coatings; however, some small areas of peeling were evident for the TiN coatings, whereas comparatively larger areas of peeling were observed for the CrN coatings. Conclusions: Our findings suggest that the CoFs for metal bracket-archwire combinations used in orthodontic treatment can be decreased by coating with Al₂O₃ and TiN thin films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.909-912
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• 2001

Lanthanide orthochromite materials have been widely studied as refractory conducting ceramics because of their electrical conductivity, oxidation resistance and high melting points. In this paper theoretical and experimental analysis about electric conductivity of the SHS prepared ceramics was carried out. The usefulness of the Seebeck-coefficient measurements as a function of P(O$_2$) is emphasized. Electronic conduction was found to be n-type in the lower P(O$_2$) range, and p-type in the higher P(O$_2$) range. The carrier concentrations were calculated as a function of P(O$_2$) and defect structure.

• Journal of the Korean Magnetics Society
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• v.15 no.3
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• pp.181-185
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• 2005

We have investigated the effects of Al codoping on the structural, electrical transport, and magnetic properties of oxide diluted magnetic semiconductor $Zn_{1-x}Cr_xO$ thin films prepared by reactive sputtering. Nondoped $Zn_{0.99}Cr_{0.01}O$ thin films show semiconducting transport behavior and weak ferromagnetic characteristic. The Al doping increases the carrier concentration and results in an decrease of resistivity and metal-insulator transition behavior. With increasing carrier concentration, the magnetic properties drastically change, exhibiting a remarkable increase of the saturation magnetization. These results show carrier-enhanced ferromagnetic order in Cr-doped ZnO.