• 한국세라믹학회지
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• 제37권6호
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• pp.537-544
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• 2000

Thin-film humidity sensor which TiO2, ZrO2, or CeO2 was added to MgCr2O4-based materials, respectively, were fabricated on the alumina substrate by using a resistant-heating evaporator. Thin films were approximately 2${\mu}{\textrm}{m}$ in grain size and shwoed porous microstructures. The resistance of the sensor decreased with increasing the relative humidity and the MgCr2O4-TiO2 sensor had the best humidity-sensing characteristics (linearity in relative humidity versus resistance).

• Progress in Superconductivity
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• 제9권1호
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• pp.85-90
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• 2007

Lanthanum aluminate($LaAlO_3$) film has been prepared on single crystal and metal substrates by dip coating method. Lanthanum acetate and aluminum were prepared via ligand exchange starting from lanthanum nitrate hexahydrate and aluminum nitrate hexahydrate in acetate glacial acetic acid solution after being refluxed. Coating solution was obtained by diluting the gel with methanol and 2-methoxyethanol to adjust the total cation concentration to 0.67 M. Precursor coated film was prepared by dip-coating with a speed of 25 mm/min on various substrates such as $LaAlO_3$ (001), MgO(001), $SrTiO_3$(001) single crystal, LMO/MgO/Ni-alloy. Thin films have been obtained by heat treating the precursor film at various temperatures from $600^{\circ}C{\sim}900^{\circ}C$ and various heating rate from $0.83^{\circ}C/min{\sim}1.25^{\circ}C/min$ under $Ar/O_2$ mixture containing 1000ppm oxygen. The films have been characterized by scanning electronic microscopy (SEM) and X-ray diffraction (XRD). XRD analysis for the prepared film showed that $LaAlO_3$ thin films with a preferred orientation of (100) plane parallel to substrate surface were obtained at $800^{\circ}C(1.11\;^{\circ}C/min)$ on LMO/MgO/Ni-alloy substrate, but the intensity decreased with the increase of heat treatment temperature.

• 한국초전도ㆍ저온공학회논문지
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• 제6권3호
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• pp.6-11
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• 2004

YBa$_2$Cu$_3$$O_{7-x}$ (YBCO) films were deposited on MgO(100) and SrTiO$_3$(100) single crystal substrates by cold-wall type MOCVD method using continuous source supplying system. Under the deposition temperature of 740∼76$0^{\circ}C$, c-axis oriented YBCO films were obtained. In case of the YBCO films deposited on MgO (100) single crystal substrate, the critical temperature (T$_{c}$) was under 81 K regardless of the deposition conditions, whereas T$_{c}$ of the YBCO films deposited on SrTiO$_3$(100) single crystal substrate was 83∼84 K. The critical current (I$_{c}$) of the YBCO film deposited on SrTiO$_3$(100) single crystal substrate for 30 min was 49 A/cm-width and the critical current density (J$_{c}$) was 0.82 MA/$\textrm{cm}^2$ to film thickness of 0.6 ${\mu}{\textrm}{m}$. I$_{c}$ increased to 84.4 A/cm-width as the deposition time increased to 50 min, but J$_{c}$ decreased to 0.53 MA/$\textrm{cm}^2$ to film thickness of 1.8 ${\mu}{\textrm}{m}$.rm}{m}$.

• E2M - 전기 전자와 첨단 소재
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• 제5권4호
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• pp.406-410
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• 1992

본 논문에서는 MgFe$_{2}$O$_{4}$ 세라믹스의 구조적 특성을 개선하기 위하여 TiO$_{2}$를 0-10[wt%] 첨가하여 세라믹스를 만들고 TiO$_{2}$가 습도센서용 MgFe$_{2}$O$_{4}$ 세라믹스의 구조적 특성에 미치는 영향을 조사하였다. 각 시편은 TiO$_{2}$가 첨가되는 양이 증대함에 따라 NgTi$_{2}$O$_{5}$의 이상이 나타났다. TiO$_{2}$의 첨가량이 6[wt%]일 때 까지는 시편의 밀도가 증가하여 기공율의 저하를 가져왔고 기공의 크기가 최소가 되는 조성은 5[wt%]의 TiO$_{2}$가 첨가되었을 때이며 이때의 평균 기공의 크기는 1615[.angs.]이었다. 따라서 5[wt%]의 TiO$_{2}$를 첨가했을 때가 기공의 크기 조절에 최적이라고 생각되며 센서용 기판으로 응용하기 적합하다고 생각된다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1376-1379
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• 2007

The effects of the MgO fabrication process on the properties of AC-PDPs were examined. MgO films were deposited by e-beam evaporation with various substrate temperatures and oxygen flow rates. MgO films were analyzed by XRD, CL and ellipsometer. Panel properties such as luminance, efficiency, discharge voltage and discharge delay time were measured with test panels. MgO films with higher temperature, smaller oxygen flow rate showed shorter discharge delay time. Also they showed smaller XRD peak intensity. These results revealed that the discharge delay time was strongly influenced by temperature and oxygen flow rate of the MgO fabrication process.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.890-893
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• 2006

Effects of the evaporation rate of MgO films using electron beam were investigated on the MgO properties and the discharge characteristics of the plasma display panel (PDP). The evaporation rate was changed from 3 ${\AA}/sec$ to 15 ${\AA}/sec$ at a substrate temperature of $300\;^{\circ}C$. MgO properties such as crystal orientation, surface roughness, contact angle, and film structure were inspected using XPS, AFM, drop shape analysis and SEM. We also studied the relation between MgO properties and PDP discharging characteristics. The minimum firing voltage and maximum efficacy were obtained at evaporation rate of 5 ${\AA}/sec$. In the MgO film deposited at 5 ${\AA}/sec$, (200) orientation was most intensive and surface roughness was minimum.

• 한국재료학회지
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• 제1권2호
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• pp.93-98
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• 1991

The as-grown $YBa_2Cu_3O_{7-x}$ superconducting thin films on MgO(100) substrate have been prepared by a reactive coevaporation method. The superconducting transition temperature, surface morphology and crystalline quality were examined as a function of the substrate temperature ranging from $450^{\circ}C$ to $590^{\circ}C$. From the reflection high energy electron diffraction (RHEED) analysis, it was found the film consisted of almost amorphous phase with a halo pattern deposited at the substrate temperature of $450^{\circ}C$. The film deposited at the substrate temperature of $510^{\circ}C$ consisted of polycrystalline phase, showing a broad ring pattern. On the other hand, for the film deposited at $590^{\circ}C$, RHEED showed spotty pattern indicating that this film consisted of single crystal phase. It has rough film surface due to the surface outgrowth. The surface outgrowth increased as the substrate temperature increased from $510^{\circ}C$ to $590^{\circ}C$. the surface outgrowth may be due to the anisotropic growth rate. The highest transition temperature obtained in this study was $Tc_{zero}$ of 83K with $Tc_{onset}$ of 88K for the film deposited at $590^{\circ}C$ using activated RF oxygen plasma.

• 한국수소및신에너지학회논문집
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• 제21권6호
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• pp.500-506
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• 2010

The metal monolith catalyst coated with 15wt% Ni/$MgAl_2O_4$ is applied to the natural gas steam reforming for hydrogen production. To address the improvement of adherence between metal monolith and catalyst coating layer, the pre-calcination temperature as well as the coating conditions of $Al_2O_3$ sol are optimized. When the Fe-Cr alloy monolith is pre-calcined at $900^{\circ}C$ for 6 h, $Al_2O_3$ layer was formed uniformly on the entire surface of the metal substrate. It is seen that the formation of $Al_2O_3$ layer on the monolith surface is essential for the uniform coating of $Al_2O_3$ sol onto the monolith substrate. The monolith catalyst coated with 10wt% $Al_2O_3$ sol shows high $CH_4$ conversion and good thermal stability as compared with the monolith catalyst without $Al_2O_3$ sol coating under severe reaction conditions with high GHSV of 30,000 $h^{-1}$ at $700^{\circ}C$. In addition, the metal monolith catalyst shows higher catalytic activity and better thermal conductivity than 15wt% Ni/$MgAl_2O_4$ pellet catalyst.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.713-715
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• 2009

Preferred orientation of MgO protection layer is controlled via adjusting diffusion of adatom between (111) plane with highest neighbor atoms and (200) plane with lowest neighbor atoms. The diffusion of adatom could be modulated by the factors such as substrate temperature, deposition rate, and extra energy applied on adatom like ion beam energy.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.663-666
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• 2004

In this paper, we have investigated the structure and dielectric properties of the $(Ba_{0.6}Sr_{0.4})TiO_3$ (BST) thin films film fabricatedon MgO(100)/Si substrate by an alkoxide-based sol-gel method. Both the structure and morphology of films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). For the MgO(100)/Si substrates, the BST thin films exhibited highly (100) orientation. The highly (100)-oriented BST thin films showed high dielectric constant, tunability, and figure of merit (FOM). The dielectric constants, dielectric loss and tunability of the BST thin films annealed at 700 C deposited on the MgO(100)/Si substrates measured at 10 kHz were 515.9, 0.0082, and 54.3 %, respectively.