• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.33-35
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• 2011

Films of CrAlN and CrZrN were deposited on a steel substrate by closed field unbalanced magnetron sputtering, and their oxidation behaviors were investigated. CrAlN films consisted of dense, polycrystalline CrN and AlN fine columns. The formed oxides consisted primarily of crystalline $Cr_2O_3$ incorporated with $Al_2O_3$. The oxide layers were thin and compact so as to make CrAlN films more protective than CrN films. In case of CrZrN films, Zr atoms were dissolved in the CrN phase. Zr atoms advantageously refined the columnar structure, reduced the surface roughness, and increased the micro-hardness. However, the addition of Zr did not increased oxidation resistance, mainly because Zr was not a protective element. All the deposited films displayed relatively good oxidation resistance, owing to the formation of the highly protective $Cr_2O_3$ on their surface. The $Cr_{40}Zr_9N$ and $Cr_{31}Zr_{16}N$ films oxidized to $Cr_2O_3$ as the major phase and ${\alpha}-ZrO_2$ as the minor one, whereas the CrN film oxidized to $Cr_2O_3$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.363-366
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• 1998

Shuttered Co-Cr thin films have been developed continuously as one of the major candidates for high density recording media. In this study, Co-26at%Cr thin films with c-axis oriented h.c.p. structure prepared by a improved facing targets sputtering system. We find that the effect of microstructural changes of sputtered Co-Cr thin films on magnetic properties and changes of crystal orientation due to variation substrate temperature.

• Honam Mathematical Journal
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• v.46 no.2
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• pp.224-236
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• 2024

This study inspects the structure of CR-product of a holomorphic statistical manifold. Findings concerning geodesic submanifolds and totally geodesic foliations in the context of dual connections have been demonstrated. The integrability of distributions in CR-statistical submanifolds has been characterized. The statistical version of CR-product in the holomorphic statistical manifold has been researched. Additionally, some assertions for curvature tensor field of the holomorphic statistical manifold have been substantiated.

• Journal of Magnetics
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• v.6 no.1
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• pp.19-22
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• 2001

Change of magnetic properties in CoCrPt/Ti perpendicular media with varying CoCrPt film thickness has been studied. As the CoCrPt film thickness increases from 25 nm, the Ms (saturation magnetization) increases rapidly at first and then more gradually. This Ms behavior is associated primarily with the formation of an "amorphous-like"reacted layer created by intermixing of CoCrPt and Ti at the CoCrPt/Ti interface and secondarily with a change of the Cr segregation mode with varying CoCrPt film thickness. Magnetic domain structure distinctively changes with increasing CsCrPt magnetic layer (ML) thickness. Also the strength of exchange coupling measured from the slope in the demagnetizing region of the M-H loop changes with ML thickness. The expansion of lattice parameters a and c at smaller film thickness suggests that the Cr segregation mode may be connected with the residual stress of the films. Finally, the negative nucleation field (Hn) shows a unique behavior with the change of strength of the exchange interaction.teraction.

• Journal of the Korean Solar Energy Society
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• v.26 no.1
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• pp.57-64
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• 2006

Cr-CrO cermet solar selective coatings with a double cermets layer film structure were prepared using a special direct current (dc) magnetron sputtering technology. The typical films structures from surface to bottom substrate were measured to be an $Al_2O_3$ anti-reflection layer on a double Cr-CrO cermet layer on an Al metal infrared reflection layer. Optical properties of optimized Cr-CrO cermet solar selective coating were absorptance (${\alpha}$) = 0.95 and emittance (${\varepsilon}$) = 0.10 ($100^{\circ}C$). Atomic force microscopy (AFM) image showed that Cr-CrO cermet film was very smooth and their grain size was also very small The results of thermal stability test showed that the Cr-CrO cermet solar selective coatings were stable for use at temperature of $400^{\circ}C$.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.369-376
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• 2000

Change of magnetic properties in CoCrPt/Ti perpendicular media with varying CoCrPt films thickness has been studied. As CoCrPt films thickness increase, the Ms(magnetization saturation) drastically increases at thinner thickness and gradually increases with further increase in thickness from 25nm. This Ms behaviour is associated with primarily the formation of "amorphous-like" reacted layer by intermixing of CoCrPt and Ti at CoCrPt/Ti interface and secondarily change of Cr segregation mode with varying the CoCrPt films thickness. Magnetic domain structure distinctively changes with increasing CoCrPt magnetic layer(ML) thickness. Also the strength of exchange coupling measured from the slope in demagnetizing region in M-H loop changes with ML thickness. Details of the above magnetic properties will be discussed. The expansion of lattice parameters a and c at thinner thickness suggests that Cr segregation mode may be connected with the residual stress of the films. Finally, negative nucleation field(Hn) behaviour with the exchange slope will be reported.

• Bulletin of the Korean Chemical Society
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• v.26 no.9
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• pp.1395-1402
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• 2005

The reaction of cis-[Cr([14]-decane)$(OH)_2]^+$ ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) with auxiliary ligands {$L_a$ = acetylacetonate (acac), oxalate (ox) or malonate (mal)} leads to a new cis-[Cr([14]-decane)(acac)]$(ClO_4)_2{\cdot}(1/2)H_2O\;(1),\;cis-[Cr([14]-decane)(ox)]ClO_4{\cdot}(1/2)H_2O\;(2)\;or\;cis-[Cr([14]-decane)(mal)]ClO_4{\cdot}(1/4)H_2O\;(3)$. These complexes have been characterized by a combination of elemental analysis, conductivity, IR and Vis spectroscopy, mass spectrometry, and X-ray crystallography. Analysis of the crystal structure of cis-[Cr([14]-decane)(acac)]$(ClO_4)_2{\cdot}(1/2)H_2O$ reveals that central chromium(III) has a distorted octahedral coordination environment and two acetylacetonate-oxygen atoms are bonded to the chromium(III) ion in the cis positions. The angle $N_{axial}-Cr-N_{axial}$ deviates by $11^{\circ}$ from the ideal value of $180^{\circ}$ for a perfect octahedron. The bond angle O-Cr-O between the chromium(III) ion and the two acetylacetonate-oxygen atoms is close to $90^{\circ}$. The bond lengths of Cr-O between the chromium and the acetylacetonate-oxygen atoms are 1.950(3) and 1.954(2) $\AA$. They are shorter than those between chromium and nitrogen atoms of the macrocycle. The IR spectra of 1, 2 and 3 display bands at 1560 {ν (C=O)}, 1710 {${\nu}_{as}$(OCO)} and 1660 $cm^{-1}$ {${\nu}_{as}$(OCO)} attributed to the acac, ox and mal auxiliary ligands stretching vibrations, respectively.

• Current Applied Physics
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• v.18 no.11
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• pp.1320-1326
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• 2018

High crystalline quality CrN thin films have been grown on $La_{0.67}Sr_{0.33}MnO_3$ (LSMO) templates by molecular beam epitaxy. The structure and magnetic properties of CrN/LSMO heterojunctions are investigated combining with the experiments and the first-principles simulation. The N?el temperature of the CrN/LSMO samples is found to be 281 K and the saturation magnetization of CrN/LSMO increases compared to that of LSMO templates. The magnetic property of CrN/LSMO heterostructures mainly comes from Cr atoms of (001) CrN and Mn atoms of (001) LSMO. The (001) LSMO induces and couples the spin of the CrN sublattice at CrN/LSMO interface.

• Journal of the Korean institute of surface engineering
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• v.34 no.3
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• pp.231-239
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• 2001

The structure and composition of Cr-nitrides formed on an electroplated hard Cr layer during an ionnitriding process was analyzed, and the growth kinetics of the Cr-nitrides was examined as a function of the ion-nitriding temperature and time in order to establish a computer simulation model prediction the growth behavior of the Cr-nitride layer. The Cr-nitrides formed during the ion-nitriding at $550~770^{\circ}C$ were composed of outer CrN and inner $Cr_2$N layers. A nitrogen diffusion model in the multi-layer based on fixed grid FDM (Finite Difference Method) was applied to simulate the growth kinetics of Cr-nitride layers. By measuring the thickness of each Cr-nitride layer as a function of the ion-nitriding temperature and time, the activation energy for growth of each Cr-nitride was determined; 82.26 KJ/mol for CrN and 83.36 Kj/mol for $Cr_2$N. Further, the nitrogen diffusion constant was determined in each layer; $9.70$\times$10^{-12}$ /$m^2$/s in CrN and $2.46$\times$10^{-12}$ $m^2$/s in $Cr_2$N. The simulation on the growth kinetics of Cr-nitride layers was in good agreements with the experimental results at 550~72$0^{\circ}C$.

• Korean Journal of Materials Research
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• v.10 no.7
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• pp.489-492
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• 2000

Three different white cast irons alloyed with Cr and Si were prepared in order to study their distribution be-havior in matrices and carbides. The specimens were produced using a 15kg-capacity high frequency induction fur-nace. Melts were super-heated to $1600^{\circ}C$, and poured at $1550^{\circ}C$ into a pepset mold. Three combinations of the alloys were selected so as to observe the distribution behavior of Cr and Si : 0.5%C-25.0%Cr-1.0%Si(alloy No. 1), 0.5%C-5.0%Cr-1.0%Si(alloy No. 2) and 2.0%C-5.0%Cr-1.0%Si(alloy No. 3). Cellular $M_7C_3$ carbides-$\delta$ferrite eutectic were developed at $\delta$ferrite liquid interfaces in the alloy No. 1 while only traces of $M_7C_3$ carbides-$\delta$ferrite eutectic were precipitated in the alloy No. 2. With the addition of 2.0% C and 5.0% Cr, ledeburitic $M_3C$ carbides instead of cellular $M_7C_3$ carbides were precipitated in the alloy No. 3. Cr was distributed preferentially to the $M_7C_3$ carbides rather than to the matrix structure while more Si was partitioned in the matrix structure rather than the $M_7C_3$ carbides. $K^m$ for Cr was ranged from 0.56 to 0.68 while that for Si was from 1.12 to 1.28. $K^m$ for Cr had a lower value with increased carbon contents. The mass percent of Cr was higher in the $M_7C_3$ carbides with increased Cr contents.