• 한국재료학회지
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• 제11권4호
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• pp.272-277
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• 2001

WO$_3$에 NiO를 첨가하여 제조한 후막형 시편의 미세구조와 전기적 성질에 대해 연구하였다. NiO 첨가에 따른 WO$_3$의 결정립 성장이 억제되었고, 입도 분포도 균일하였으나 첨가량에 따른 결정립 크기 변화정도는 작았다. 산소 분압 감소로 WO$_3$의 전도성은 증가하였고, NiO 첨가에 의해 고용한계 이하에서는 전도성이 증가하였고, 이상에서는 전도성이 감소하였다. 온도 증가에 따라 외인성 (extrinsic) 구간에서는 전도성 변화가 적었고, 고온의 진성 (intrinsic) 구간에서는 전도도가 급격히 증가하였으며, 이들의 중간 온도에서는 산소흡착에 따라 전도도가 감소하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.61-66
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• 2001

NiO-doped $WO_3$ thick films were prepared by a screen printing technique. The electrical property and microstructure of the films were investigated with the partial pressure of oxygen and the amount of NiO. The grain size of NiO-doped $WO_3$ was smaller than that of undoped $WO_3$, but the grain size of 0.1, 1, 10 mol% NiO-doped $WO_3$ were nearly the same. The electrical conductance of the $WO_3$ thick films decreased with the oxygen partial pressure, and increased with the amount of NiO to the limit of solid solution. The variation of the electrical conductance with temperature is not so large in the extrinsic region, but it changed rapidly in the intrinsic region. The conductance decreased with adsorption of oxygen in the intermediate range between the extrinsic and intrinsic region.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 추계총회,초청강연,특별강연,연구발표회
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• pp.63.1-63
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• 2000

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.643-643
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• 2013

Recently, synthesis of low-dimensional nanostructures is gaining more importance due to their structural properties and growing potential applications. On the other hand, luminescent materials doped with rare earth ions have drawn immense attention. The commercial phosphors are based on many host materials. Among them, tungstates are being currently investigated by many research groups owing to a wide range of applications. Tungstates are formed by different metal cations (e.g., SrWO4, Na2WO4, NiWO4, Cr2WO6, and ZrW2O8) and their structure depends on the size of the metal cation. Tungstates with large bivalent cations (${\gg}0.1\;nm$) have the scheelite structure and the wolframite structure with smaller ions (＜0.1 nm). Strontium tungstate has the scheelite structure which is tetragonal with space group I41/a. The luminescent properties of the tungstate have been extensively explored in application fields such as sensors, detectors, lasers, photoluminiscent devices, photo catalysts, etc. In this work, we synthesized SrWO4 phosphors with different Eu3+ concentrations by using a facile route. The morphology was analyzed by using a field-emission scanning electron microscope, which exhibits the spherical shape. Transmission electron microscope image revealed the spheres composed of nanoparticles. X-ray diffraction patterns confirmed their tetragonal shape. The photoluminescence excitation and emission spectra were analyzed by varying the Eu3+ concentration, which shows a dominant red emission.