• Journal of the Korean Magnetics Society
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• v.8 no.6
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• pp.357-361
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• 1998

For CoZr/Ag/CoCr trilayered films deposited by DC and FR magnetron sputtering method, ferromagentic resonance experiments have been used to investigate the dependence of the exchange coupling between CoZr and CoCr layers separated by Ag layer on the thickness of the Ag layer. The coupling strength K increases with increasing Ag thickness up to 10 $\AA$ with a maximum value of 748 Oe, but oscillates with increasing Ag thickness in the range from 20 to 100 $\AA$. The coupling strength is positive for all samples. Hence, it seems that the exchange coupling between CoZr and CoCr layers separated by Ag layer is ferromagnetic.

• Journal of the Korean Magnetics Society
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• v.6 no.2
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• pp.86-92
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• 1996

The structural, magnetic and magnetoresistance properties of Co/Ag multilayer films prepared by thermal coevaporation were studied. When the Ag layer was $60{\AA}$ thick, the Co layer behaved ferromagnetically even with the thickness of $5{\AA}$. However, when the thickness of Ag layer was $30{\AA}$ and that of Co layer was less than $15{\AA}$ thick, the Co layer became discontinuous and the islands of Co behaved mostly superpararnagnetically. The maximum MR ratio, 6.1% was obtained in the $3000{\AA}\;Ag30{\AA}/Co10{\AA}$ Ag30 A ICo 10 A discontinuous multilayer. Agglomeration of the Co layer was promoted by annealing and hence MR ratio increased when the thickness of Ag layer was thinner than $15{\AA}$. The SiO underlayer enhanced the MR ratio in the $1000{\AA}$ thick multilayer via the layer structure improvement.

• Resources Recycling
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• v.5 no.1
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• pp.29-33
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• 1996

The cominnn plocesses lor rccoremg silver irom silvcr conlaincd waster are the lcachmg silver hy HNO;. the srlcctive precipilillion of sliver ion lo AgCl and thc rcduchon of Ag wrfh ;I proper reductant. In this sludy, thc reduction of AgCI lo Ag was invesllngated by using Na, CO, as a rcd\icta~lt. The variations wcic reaction time. ttmpcrarure thc amount of NalCO, . and the resulls %, ere analyzcd by using sialist~c:d tecl~niques such as the ]polynomial rcgressiun analysis and the response surh~ce method. More than Yh% Ag analyzed was rcduced 1rtm AgCI at 62UT. I hour ullder condillon of 2 stnlchio~nctric ratio of Na iCO, !AgCI.

• Journal of the Korean Magnetics Society
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• v.5 no.1
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• pp.48-53
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• 1995

The structure, magnetic properties and magnetoresistance phenorrena of Ag-Co nano-granular alloy films prepared by a thermal co-evaporation were studied. Supersaturated fee Ag-Co solid solution and fee Co clusters coexisted in the as-deposited state. As Co content increases from 20 to 55 at.% Co, the grain size of the Ag matrix decreases from 147 to $67{\AA}$, and the Co solubility in the Ag matrix increases from 2.5 to 6.7%. Ag-Co alloy films having composition below 25 at.% Co showed mainly superparamagnetic behavior and above that composition, they showed both paramagnetic and ferromagnetic l::ehavior in the as-deposited state. The maximum magnetoresistance of 19% at R. T. and 10 kOe was obtained in the as-deposited 30 at.% Co alloy film. Heat treatment did not improve the MR ratio tecause most of the Co was already precipitated in the as-deposited state.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.811-816
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• 2006

The single layered magnetic thin films with anisotropic magnetoresistance behavior have advantage on micro integration due to their low cost in manufacturing. Although the conventional MCo (M=Cu, Ag) amorphous ribbons using a rapid solidification process have showed appropriate for magnetic property for bulk devices, they are not appropriate for micro-scale devices due to their brittleness. We prepared the thermal evaporated 100 nm-thick $Cu_{1-x}Co_x\;and\;Ag_{1-x}Co_x(x=0.1{\sim}0.7)$ films on silicon wafers and investigated the magnetic property of the as-depo films such as magnetization and magnetoresistance ratio. We confirmed that the maximum MR ratio of 1.4 and 2.6% at the external field of 0.5 Tesla in $CuCo_{30},\;AgCo_{40}$ films, respectively. Our result implies that AMR may be slightly less than those of the conventional CuCo and AgCo ribbons due to surface scattering, but their AMR ratio be enough for micro-scale application with easy integration compatibility for the process without surface oxidation.

• Journal of the Korean Chemical Society
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• v.32 no.6
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• pp.520-527
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• 1988

The crystal structures of $Co^{2+}\;and\;Ag^+\;exchanged\;zeolite\; A,\; Ag_6Co_3$-A(a = 12.131(5)$\AA$) and $Ag_3Co_{4.5}$-A(a = 12.145(1)$\AA$), have been determined by single crystal X-ray diffraction techniques. Both structures were solved and refined in the cubic space group Pm3m at 21(1)$^{\circ}C$. Full-matrix leastsquares refinement converged to the final error indices of R1 = 0.045 and R2 = 0.041 for $Ag_3Co_{4.5}-A,\; and\; R1 = 0.066\; and\; R2 = 0.076\; for\; Ag_6Co_3$-A using the 258 and 189 reflections, respectively, for which I > 3$\sigma$(I). Both structures indicate that CO(Ⅱ)ions are coordinated by three framework oxygens; the Co(II) to O(3) distances are 2.118(4)$\AA$ for $Ag_3Co_{4.5}$-A and 2.106(1)$\AA$ for $Ag_6Co_3-A$, respectively. In each structure, the angle substended at Co(II), O(3)-Co(II)-O(3) is ca 120°, close to the idealized trigonalplanar value. $Co^{2+}$ ions prefer to 6-ring sites and $Ag^+$ ions prefer to 8-ring site when total number of cations is more than 8. The crystals of hydrated and dehydrated $Ag_{12-2x}Co_x-A (x > 4.5)$ had no crystalline diffraction pattern, indicating the apparent exchange limit of $Co^{2+}\; into\; Ag_{12}-A\; is\; 4.5 Co^{2+}$ ions per unit cell. $Co^{2+}$ ions hydrolyze $H_2O$ molecules and $H_3O^+$ concentraction is accumulating. These $H_3O^+$ ions destroy the zeolite structures.

• Journal of the Korean Magnetics Society
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• v.11 no.2
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• pp.63-71
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• 2001

The effects of an Ag seed layer on the magnetic properties and the microstructural evolution of SmCo/Cr thin films deposited on glass substrates were investigated. Coercivity of the films is 2.0 kOe when the thickness of Ag seed layer was 1nm thick, but it increased to 2.7 kOe when the Ag seed layer thickness is 3 nm. The increase of coercivity for film with 3 nm-thick Ag is due to roughness of Cr and grain size of Cr by the Ag microbumps. Ar partial pressure influenced on the formation of Ag microbumps, for example, they were formed at 5 mTorr when Ag thickness was 1 nm. The mechanism of magnetization reversal of the SmCo films changed from domain wall motion to domain rotation as the Ag inserted. This was thought to be due to inhibition of domain wall motion by the reduction of Cr grain size and the increase of roughness.

• Journal of the Korean Magnetics Society
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• v.21 no.6
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• pp.214-218
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• 2011

In this study, we have systematically investigated the effect of sputtering conditions on the microstructural properties of Ag/CoFeB thin film on MgO substrate. It was found that the crystallinity and surface roughness of the Ag film strongly depends on the Ar sputtering pressure and sputtering power. Epitaxial growth of Ag(100) film on MgO(100) substrate was achieved under the sputtering conditions of high sputtering power and elevated temperature. XRR (X-ray reflectivity) and high-resolution TEM (transmission electron microscopy) measurements also revealed the interfacial roughening in the Ag/CoFeB interface due to the island structure formation and intermixing between Ag and CoFeB.

• Journal of the Korean Magnetics Society
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• v.12 no.3
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• pp.94-98
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• 2002

Sputtering conditions and various underlayer such as Al, Cu, Ni, Cr, Ag, Mg, Fe, Co, Pd, Au, Pt, Mo and Hf were investigated for coercivity enhancement of 20 nm Ti/CoCrPt thin films in order to increase the coercivity of the films thinner than 20 nm. Among them, Ag and Mg were effective to increase the coercivity. Particularly 2 nm Ag was very effective to increase the coercivity and nucleation field as well as to reduce ${\alpha}$ value in CoCrPt thin film such that the coercivity of 2 nm Ag/18 nm Ti/10 nm CoCrPt film was 2200 Oe. However, it seemed that other coercivity enhancement mechanism operated in CoCrPt films because Ti (002) preferred texture was not developed with Ag underlayer contrary to a general expectation. And the coercivity and nucleation field were decreased when glass substrate with rougher surface was used.

• Journal of Oral Medicine and Pain
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• v.31 no.2
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• pp.167-176
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• 2006

Recent studies have shown that there are significant increasing facial asymmetry using 3-dimensional imaging. This study use panorama view and PA cephalograph that were low in price and make good use in dentistry. For this study, 35 persons without remarkable malocclusion were selected, they had panorama view and PA cephalograph, make written questionnaire about facial asymmetry cognition and masticatory pattern. Data obtained were statistically processed by the SPSS Windows program and the results of this study were as follows: 1. There were significant difference between Rt and Lt. on Co-Go, Co-Ag, Co-Go-Ag, Go-Me- Ag. 2. In panorama view, There were significant difference between Rt. and Lt Co-Ag that chewing right side, Rt. and Lt. Co-Go that chewing left side, 3. In PA cephalograph view, There were significant difference in Rt. and Lt. Cg-Go, Rt. and Lt. Co-Ag that chewing right side, Rt. and Lt. Cg-Go that chewing left side 4. There were significant difference in Rt. and Lt. Co-Go, CO-si-CR, go-ME-Ag that cogniting facial asymmetry.