• Journal of Sensor Science and Technology
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• v.7 no.1
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• pp.45-50
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• 1998

Platinum-Cobalt alloy thin films were deposited on $Al_{2}O_{3}$ substrate by magnetron cosputtering for RTD temperature sensors. We made Pt-Co alloy resistance patterns on the $Al_{2}O_{3}$ substrate by lift-off method and investigated the physical and electrical characteristics of these films under various conditions, the input power, working vacuum, annealing temperature and time, and also after annealing these films. The resistivity and sheet resistivity of these films were decreased with increasing the annealing temperature. At input power of Pt : $4.4\;W/cm^{2}$, Co : $6.91\;W/cm^{2}$, working vacuum of 10 mTorr and annealing conditions of $800^{\circ}C$ and 60 min, the resistivity and sheet resistivity of Pt-Co thin films was $15{\mu}{\Omega}{\cdot}cm$ and $0.5{\Omega}/{\square}$, respectively and the TCR value of Pt-Co alloy thin films with thickness of $3000{\AA}$ were $3740ppm/^{\circ}C$ in the temperature range of $25{\sim}600^{\circ}C$. These results indicate that Pt-Co alloy thin films have potentiality for the RTD temperature sensors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.47-52
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• 2002

A processing method is developed for preparing sol-gel derived $Pb(Zr_{1-x}Ti_x)O_3$ (x=0.5) thin films on Pt-Ir($Pt_{80}Ir_{20}$)-alloy substrates. The as-deposited layer was dried on a plate in air at $70^{\circ}C$. And then it was baked at $1500^{\circ}C$, annealed at $450^{\circ}C$ and finally annealed for crystallization at various temperatures ranging from $580^{\circ}C$ to $700^{\circ}C$ for 1hour in a tube furnace. The thickness of the annealed film with three layers was $0.3{\mu}m$. Crystalline properties and surface morphology were examined using X-ray diffractometer (XRD). Electrical properties of the films such as dielectric constant, C-V, leakage current density were measured under different annealing temperature. The PZT thin film which was crystallized at $600^{\circ}C$ for 60minutes showed the best structural and electrical dielectric constant is 577. C-V measurement show that $700^{\circ}C$ sample has window memory volt of 2.5V and good capacitance for bias volts. Leakage current density of every sample show $10^{-8}A/cm^2$ r below and breakdown voltage(Vb) is that 25volts.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1485-1487
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• 1997

Platinum-Cobalt alloy thin films were deposited on $Al_2O_3$ substrates by co sputtering for RTD temperature sensors. We made Pt-Co alloy resistance patterns on $Al_2O_3$ substrate by lift-off method and investigated the physical and electrical characteristics of these films under sputtering conditions (; the input power, working vacuum), annealing conditions (; temperature, time) and also after annealing these films. After the annealing treatment at $800^{\circ}C$ for 60min, the resistivity and sheet resistivity of Pt-Co thin films was $0.0302{\mu}{\Omega}{\cdot}cm$ and $0.1{\Omega}/{\square}$, respectively, and the TCR value of Pt-Co RTD was $3600ppm/^{\circ}C$ in the temperature range of $25{\sim}400^{\circ}C$. These results indicate that Pt-Co thin films have potential for the excellent RTD temperature sensors.

• Korean Journal of Materials Research
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• v.17 no.5
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• pp.283-288
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• 2007

This study aimed to investigate the effects of the seed layer with copper electroplating on the surface morphology of copper foil. Three kinds of seed metal such as platinum, palladium, Pt-Pd alloy were used in this study. Electrodeposition was carried out with the constant current density of 200 $mA/cm^2$ for 68 seconds. Electrochemical experiments, in conjunction with SEM, XRD, AFM and four-point probe, were performed to characterize the morphology and mechanical characteristics of copper foil. Large particles were observed on the surface of the copper deposition layer when a copper foil was electroplated on the 130 nm thickness of Pd, Pt-Pd seed layer. However, a homogeneous surface, low resistivity was obtained when the 260 nm thickness of Pt, Pt-Pd alloy seed layer was used. The minimum value of resistivity was 2.216 ${\mu}{\Omega}-cm$ at the 260 nm thickness of Pt-Pd seed layer.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2544-2546
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• 1998

The electrical and physical charateristics of Pt-Co alloy thin films on $Al_2O_3$ substrate, deposited by r.f cosputtering respectively, were analyzed with thickness of thin films ($1700{\sim}10000{\AA}$) and increasing annealing temperature ($800{\sim}1000^{\circ}C$). At input power of Pt : 4.4 W/$cm^2$, Co : 6.91 W/$cm^2$, working vacuum of 10 mTorr and annealing conditions of $1000^{\circ}C$) and 60 min, the resistivity and sheet resistivity of Pt-Co thin films with thickness of $3000{\AA}$ was $15{\mu}{\Omega}{\cdot}cm$ and 0.5 ${\Omega}/{\square}$, respectively. The TCR value of Pt-Co alloy thin films was measured with various thickness of thin films and annealing conditions. The optimum TCR value of 3850 ppm/$^{\circ}C$ in temperature range($200{\sim}400^{\circ}C$) is gained under conditions $3000{\AA}$ of thin films thickness and $1000^{\circ}C$ of annealing temperature. The thermal charateristics of Pt-Co micro heaters were analysed with Pt-Co RTD integrated on the same substrate. In the analysis of characteristics of Pt-Co micro heaters, the Pt-Co micro heaters with thickness of $3000{\AA}$ and annealing temperature of $1000^{\circ}C$ had a good linearity and temperature is up to $468.2^{\circ}C$ with 2.1 watts of the heating power.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.6
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• pp.549-555
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• 2019

Electrocatalysis of oxygen reduction reaction (ORR) using Pt nanoparticles or bimetal on carabon was studied. Currently, the best catalyst is platinum, which is a limited resource and expensive to commercialize. In this paper, we investigated the cheaper and more active electrocatalysts by making Pt nanoparticles and adding 3D transition metal such as copper. Electrocatalysts were obtained by chemical reduction based on ethylene glycol solutions. Elemental analysis and particle size were confirmed by XRD and TEM. The electrochemical surface area (ECSA) and activity of the catalyst were determined by electrochemical techniques such as cyclic voltammetry and linear sweep voltammetry method. The commercialized Pt support on carbon (Pt/C, JM), synthesis Pt/C and synthesis Pt3Cu1 alloy nanoparticles supported on carbon were compared. We confirmed that the synthesized Pt3-Cu1/C has high electrochemical performance than commercial Pt/C. It is expected to develop an electrocatalyst with high activity at low price by increasing the oxygen reduction reaction rate of the fuel cell.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.354-357
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• 1995

Measurements of X-ray diffuse scatterings were made in disordered single crystal of Fe-28.3 at%Pt Invar alloy around a 200-Bragg peak in a wide temperature range between 15 K and 300 K. Observed diffuse scatterings were almost spherical, suggesting a homogeneous disordered alloy. However, the qdependence of the observed thermal diffuse scattering was different from the usual type, indicating a possibility of existence of local distortion of lattice accompanied by a large gradient of stress.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.253-253
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• 2012

The effects of oxidation on the order-disorder transition in NiPt bimetallic alloy crystal have been investigated using in-situ synchrotron x-ray scattering technique. The temperature dependence of the crystal structure and the order parameter were measured during in-situ heating and cooling under vacuum and oxygen environments. The order-disorder transition temperature of NiPt alloy crystals in vacuum was between $615^{\circ}C$ and $627^{\circ}C$. On the other hand under oxygen environment, the transition temperature decreases by about $31^{\circ}C$ after the oxidation. The change of the transition temperature can be explained by the formation of NiO crust on the surface of NiPt crystal, which alters the composition of the Ni and Pt atoms. Since the transition temperature depends sensitively on the Ni-Pt composition, the transition temperature changes as Ni atoms diffuse out to form NiO.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.04a
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• pp.66-67
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• 2002

No Abstract, See Full Text

• Proceedings of the Korean Magnestics Society Conference
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• 2005.12a
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• pp.101-101
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• 2005