• 한국재료학회지
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• 제14권8호
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• pp.595-599
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• 2004

We investigated the structural, electrical and magnetic properties of Mn-doped $CuAlO_2$ delafossite ceramics ($CuAl_{1-x}Mn_{x}O_2,\;0\le\;x\;\le0.05$), synthesized by solid-state reaction method in an air atmosphere at a sintering temperature of $1150^{\circ}C$. The solubility limit of Mn ions in delafossite $CuAlO_2$ was found to be as low as about 3 $mol\%$. Positive Hall coefficient and the temperature dependence of conductivity established that non-doped $CuAlO_2$ ceramic is a variable-range hopping p-type semiconductor. It was found that the Mn-doping in $CuAlO_2$ rapidly reduced the hole concentration and conductivity, indicating compensation of free holes. The analysis of the magnetization data provided an evidence that antiferromagnetic superexchange interaction is the dominant mechanism of the exchange coupling between Mn ions in $CuAl_{1-x}Mn_{x}O$ alloy, leading to an almost paramagnetic behavior in this alloy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1488-1490
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• 2000

ZnO:Cu thin films are deposited by using an RF magnetron co-sputtering system with Cu chips attached on ZnO target. Structural and electrical properties are analyzed as a function of deposition conditions, such as Cu chip areas, $O_2/(Ar+O_2)$ ratios, and working pressures, The results show that a higher electrical resistivity above $10^{10}$ ${\Omega}cm$ along with an excellent c-axial growth can be easily achieved by Cu-doping. SAW filters based on the ZnO:Cu films are also fabricated to estimate the electric-mechanical coupling coefficient($K^{2}_{eff}$). Higher $K^{2}_{eff}$ and lower insertion losses are observed for ZnO:Cu films, compared with those for ZnO films.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.576-577
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• 2008

ZnS:Cu,Cl blue-green phosphors were prepared by conventional solid state reaction. Copper activator of different concentrations was doped into ZnS structure at two firing steps. The luminescence characteristics dependent on $Cu^{2+}$ doping concentration of the phosphors has been investigated for inorganic electroluminescent device.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.157-157
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• 2010

Programmable Metallization Cell (PMC) is a memory device based on the electrolytical characteristic of chalcogenide materials. PMC components of Ge-Se doped with Ag ions were studied with help of the previous studies and copper was used for metallic ions taking into account of economy of components. In this study, we investigated the nature of thin films formed by photo doping of Cu ions into chalcogenide materials for use in solid electrolyte of programmable metallization cell devices. We were able to do more economical approach by using copper which play role of electrolyte ions. The results imply that a Cu-rich phase separates owing to the reaction of Cu with free atoms from chalcogenide materials.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.346-350
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• 2002

The effect of Ca-doping on the superconducting properties of Nd-Ba-Cu-O bulk superconductors, fabricated by the oxygen-controlled melt growth process, has been systematically investigated. Various c-axis textured bulk samples were grown using precursors with the nominal compositions of N $d_{1.8-x}$C $a_{x}$B $a_{2.4}$C $u_{3.4}$ $O_{y}$ (x = 0.00, 0.02, 0.05, 0.10, 0.15) in a reduced oxygen atmosphere of 1% $O_2$ in Ar. Magnetization measurements revealed that the critical temperatures( $T_{c}$) were almost linearly depressed from 95K to 86K with increasing the Ca dopant from x = 0.0 to 0.15, respectively, and thus critical current densities( $J_{c}$) at 77K and for H//c-axis of specimens were gradually degraded with increasing x. Compositional analyses revealed that although the amounts of the Ca dopant both in NdB $a_2$C $u_3$ $O_{y}$(Nd123) and N $d_4$B $a_2$C $u_2$ $O_{10}$(Nd422) were increased with increasing x, only less than half of the initial Ca compositions were detected in melt-grown Ca-doped Nd-Ba-Cu-O bulk crystals. The supression of $T_{c}$ is attributed to an increased Nd substitution for the Ba site in the Nd123 superconducting matrix with increasing the amount of the Ca dopant.t.opant.t.t.t.t.t.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2009년도 Korea Superconductivity Society Meeting 2009
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• pp.50-50
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• 2009

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2008년도 High Temperature Superconductivity Vol.XVIII
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• pp.88-88
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• 2008

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.22-22
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• 2010

0.1~5.0 at% CuO doped ZnO specimens were fabricated by a commercial ceramic process and sintered at 900~$1200^{\circ}C$ for 3h in air. The relative densities were over 97% for all samples and average grain size increased with CuO doping. The defect trap levels i.e. ionization energies of defects were increased linearly with CuO contents as 0.2 eV to 0.7 eV by using admittance spectroscopy and dielectric functions. The apparent activation energies of grain boundaries were varied but in the range of 0.96~1.1 eV. Dielectric constant were increased with CuO contents and sintering temperatures.

• 태양에너지
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• 제17권3호
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• pp.51-57
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• 1997

열벽 증착(hot-wall evaporation)방법으로 Cu를 첨가한 ZnTe박막을 성장하였다. doping을 하지 않은 ZnTe박막의 전기 전도형은 p-형으로 전기 전도도는 $10^{-6}({\Omega}{\cdot}cm)^{-1}$을 정도로 매우 낮았다. 첨가한 Cu의 양에 따라 전기 전도도는 $10^2({\Omega}{\cdot}cm)^{-1}$까지 증가하였으나 이동도는 크게 변하재 않았다. Cu를 매우 많이 첨가한 경우는 금속과 같은 전기 전도도를 관찰하였다.

• Progress in Superconductivity
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• 제13권3호
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• pp.158-162
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• 2012

$Y(Pr)Ba_2Cu_4O_8$ system is one of the most studied high temperature superconductors. Substitution of Pr for Y in this system suppresses $T_c$ and superconductivity finally disappears at a high Pr doping. There are competing theories for the suppression of $T_c$ but systematic experimental results are very rare. In order to find the change in Fermi surface topology which can affect the superconductivity, we have performed angle-resolved photoemission studies on single crystal samples of $YBa_2Cu_4O_8$ and $PrBa_2Cu_4O_8$. While the Fermi surface of $YBa_2Cu_4O_8$ shows a similar topology to those of other cuprates, we observe only 1D like band structures in $PrBa_2Cu_4O_8$. We find no significant differences in the chain band for both samples.