• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1122-1123
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• 2006

Mn-Fe oxide and Mn-Fe oxide/$ZrO_2$(50wt%/50wt%) were prepared by ball milling method. XRD data of the prepared samples revealed that hematite and ferrite phase coexisted. Water splitting at 1273K, after thermal reduction at 1573K, was performed 4 times for the samples. Hydrogen production amount was analyzed by GC with TCD detector. Water splitting capacity of Mn-Fe oxide was improved by ball milling with $ZrO_2$.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 추계학술발표회논문집(2)
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• pp.533-538
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• 1996

40$0^{\circ}C$ $H_2O$, D$_2$O 및 $O_2$ 분위기에서 Zr-2.5wt% Nb 합금의 부식거동을 비교.분석하였다. Zr-2.5wt% Nb 합금은 열처리에 따른 조직에 따라 각각의 부식매질에 대해 부식거동이 큰 차이를 보이고 있으나, 형성된 oxide는 열처리 및 부식매질에 관계없이 monoclinic ZrO$_2$ 만이 관찰되었다. 급냉조직인 martensitic $\alpha$'-Zr 상과 소둔처리 조직의 준안정상인 $\beta$-Zr 상의 경우. 부식분위기에 매우 민감하여, D$_2$O, H $_2$O, $O_2$ 순으로 큰 부식속도를 보였다. 반면, 안전성들인 $\alpha$-Zr과 $\beta$-Nb 상의 경우, 부식 분위기에 따른 별다른 부식거동 차이를 보이지 않았다. 이들 실험 결과를 바탕으로 월성형 원자로 압력관의 부식특성을 분석하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.245-251
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• 2017

Niobium doped zirconium oxide (Nb-Zr-O:NZO) thin films were fabricated on Si substrates by a sol-gel technique with an annealing temperatures of $500{\sim}1000^{\circ}C$ in air ($N_2:O_2=3:1$) for 20 minutes. It was found that the NZO film is based on tetragonal $ZrO_2$ polycrystalline structure with the Nb 5+ ion state and there is almost no diffusion of Nb or Zr to Si substrate. The relative dielectric constant for the NZO film with the Nb composition of 30 mol% and annealed at $800^{\circ}C$ was around 40. The root mean roughness was 1.02 nm. In addition, the leakage current of NZO films was as low as $10^{-6}A/cm^2$ at 4.4 V.

• 한국세라믹학회지
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• 제23권6호
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• pp.52-58
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• 1986

$Pb(Zr_{0.525} Ti_{0.475})O_3$ piezoelectric ceramics both unmodified and doped with NiO were prepared by the conventional oxide techniques using sintering temperature from 900 to to 125$0^{\circ}C$. The difference in densification process between unmodified and NiO doped PZT ceramics was studied by shrinkage vs. firing temperatures and it was caused by increasing defect concentration in calcining process of NiO doped PZT ceramics. And nickel oxide solubility limit for $Pb(Zr_{0.525} Ti_{0.475})O_3$ ceramics is shown to be at the range from 0.2wt% to 0.5wt% from this defect model micro-structures dielectric and piezolectric properties of Nio doped PZT ceramics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.85-86
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• 2006

Chemical mechanical polishing (CMP) technology has been widely used for global planarization of multi-level interconnection for ULSI applications. However, the cost of ownership and cost of consumables arc relatively high because of expensive slurry. In this paper, in order to save the costs of slurry, the original silica slurry was diluted by de-ionized water (DIW). And then, $ZrO_2$, abrasives were added in the diluted silica slurry (DSS) in order to promote the mechanical force of diluted slurry. We have also investigate the possibility of mixed abrasive slurry (MAS) for the oxide CMP application.

• 한국세라믹학회지
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• 제31권9호
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• pp.969-974
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• 1994

After adding 8Y-ZrO2 powders to 3Y-ZrO2 powders at ratios of 0, 33, 50, 67, and 100% by weight, the mixed yttria-stabilized zirconia specimens were fabricated into thin plate using tape~casting method and then sintered at 150$0^{\circ}C$ for 4h in air. The crystalline structure, microstructure and electrical properties of the sintered zirconia thin plates were investigated by using X-ray diffractometer, scanning electron microscope and impedance analyser, respectively. At the temperatures higher than 75$0^{\circ}C$, the sintered thin plate with 33% 8Y-ZrO2 content shows higher mechanical properties and lower electrical resistivity than 8Y-ZrO2 thin plate which is generally used as an electrolyte for solid oxide fuel cells. This is due to the fact that the zirconia thin plates with low 8Y-ZrO2 content maintain the slope of low temperature region up to high temperatures, whereas at temperatures higher than 50$0^{\circ}C$ the slope decrease in the zirconia thin plates with high 8Y-ZrO2 content.

• 한국분말재료학회지
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• 제19권6호
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• pp.429-434
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• 2012

With increase in operating temperature of gas turbine for higher efficiency, it is necessary to find new materials of TBC for replacement of YSZ. Among candidate materials for future TBCs, zirconate-based oxides with pyrochlore and fluorite are prevailing ones. In this study, phase structure and thermal conductivities of $(La_{1-x}Gd_x)_2Zr_2O_7$ oxide system are investigated. $(La_{1-x}Gd_x)_2Zr_2O_7$ system are comprised by selecting $La^{3+}/Gd^{3+}$ as A-site ions and $Zr^{4+}$ as B-site ion in $A_2B_2O_7$ pyrochlore structures. With powder mixture from each oxide, $(La_{1-x}Gd_x)_2Zr_2O_7$ oxides are fabricated via solid-state reaction at $1600^{\circ}C$. Either pyrochlore or fluorite or mixture of both appears after heat treatment. For the developed phases along $(La_{1-x}Gd_x)_2Zr_2O_7$ compositions, thermal conductivities are examined, with which the potential of $(La_{1-x}Gd_x)_2Zr_2O_7$ compositions for TBC application is also discussed.

• 한국진공학회지
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• 제12권S1호
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• pp.83-87
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• 2003

Zirconium oxide films have been synthesized by radio-frequency magnetron sputtering deposition on n-Si(001) substrate with metal zirconium target at variant $O_2$ partial pressures. The influences of $O_2$ partial pressures of the morphology, deposition rate, microstructure, and the dielectric constant of $ZrO_2$ have been discussed. The results show that deposition rate of $ZrO_2$ films decreases, the roughness, and the thickness of the native $SiO_2$ interlayer increases with the increase of $O_2$ partial pressure. $ZrO_2$ films synthesized at low $O_2$ partial pressure are amorphous and monoclinic polycrystalline in nanometer scale at low $O_2$ partial pressure. The relative dielectrics of $ZrO_2$ films are in the range of 12 to 25.

• E2M - 전기 전자와 첨단 소재
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• 제16권9호
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• pp.61.1-61
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• 2003

Stoichiometric, uniform, amorphous ZrO$_2$ films with an equivalent oxide thickness of ∼1.5nm and a dielectric constant of ∼18 were deposited by an atomic layer controlled deposition process on silicon for potential application in meta-oxide-semiconductor(MOS) devices. The conduction mechanism is identified as Schottky emission at low electric fields and as Poole-Frenkel emission at high electric fields. the MOS devices showed low leakage current, small hysteresis(〈50mV), and low interface state density(∼2*10e11/cm2eV). Microdiffraction and high-resolution transmission electron microscopy showed a localized monoclinic phase of ${\alpha}$-ZrO$_2$ and an amorphous interfacial ZrSi$\_$x/O$\_$y/ layer which has a correspondign dielectric constant of 11

• Bulletin of the Korean Chemical Society
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• 제28권1호
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• pp.53-58
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• 2007

In the dehydrogenation of ethylbenzene to styrene, CO2 could play a role as an oxidant to increase conversion of ethylbenzene and stability as well over TiO2-ZrO2 mixed oxide catalysts. TiO2-ZrO2 catalysts were prepared by co-precipitation method and were characterized by BET surface area, bulk density, X-ray diffraction, temperature programmed desorption of NH3 and CO2. These catalysts were found to be X-ray amorphous with enhanced surface areas and acid-base properties both in number and strength when compared to the respective oxides (TiO2 and CO2). These catalysts were found to be highly active (> 50% conversion), selective (> 98%) and catalytically stable (10 h of time-on-stream) at 600 oC for the dehydrogenation of ethylbenzene to styrene. However, in the nitrogen stream, both activity and stability were rather lower than those in the stream with CO2. The TiO2-ZrO2 catalysts were catalytically superior to the simple oxide catalysts such as TiO2 and ZrO2. The synergistic effect of CO2 has clearly been observed in directing the product selectivity and prolonging catalytic activity.