• 한국전기전자재료학회논문지
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• 제26권1호
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• pp.64-67
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• 2013

$Fe_3O_4$(magnetite) having half metallic property attracts great attention material with high curie temperature in spintronics. $Fe_3O_4$ thin films and nanowires were grown onto c-$Al_2O_3$(0001) at various substrate temperatures. $Fe_3O_4$ films deposited from 300 to $600^{\circ}C$ are influenced by thermal stress induced from mismatch of thermal expansion coefficient between $Fe_3O_4$ and $Al_2O_3$ (0001) substrate. The $Fe_3O_4$ nanowires grown at $640^{\circ}C$ showed a diameter of 130 nm and a length of $2-10{\mu}m$. The nanowire arrays fabricated by pulsed laser deposition technique have high coercivity($H_c$) of 608 Oe and Squareness($M_r/M_s$) of 0.68 in perpendicular direction.

• Nano
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• 제13권11호
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• pp.1850125.1-1850125.12
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• 2018

To reduce the imbalance of impedance matching between the magnetic metal nanowires and free space, $Fe/TiO_2$ core/shell nanowire arrays with different diameters were fabricated in the templates of anodic aluminum oxide membranes by electrodeposition. The influences of the microstructure on the microwave absorption properties of the $Fe/TiO_2/Al_2O_3$ composites were studied by the transmission/reflection waveguide method. It was demonstrated experimentally that both the interfacial polarization and the diameter of the $Fe/TiO_2$ core/shell nanowires have critical effects on the microwave absorption properties. We also investigated the angle dependence of the microwave absorption properties. Due to the interfacial polarization and associated relaxation, the $Fe/TiO_2/Al_2O_3$ composites exhibited optimal microwave absorption properties when microwave propagation direction was accordant with the axis of the nanowires. Finally, we managed to obtain an optimal reflection loss of below -10 dB (90% absorption) over 10.2-14.8 GHz, with a thickness of 3.0 mm and the minimum value of -39.4 dB at 11.7 GHz.

• 마이크로전자및패키징학회지
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• 제30권4호
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• pp.91-97
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• 2023

전기화학적 이산화탄소 (CO₂) 환원은 CO₂를 고부가가치의 탄소화합물로 전환하는 매우 유망한 방법이다. 본 논문에서는 양극 산화법과 원자층 증착법을 이용하여 전기화학적 CO₂ 환원용 SnO₂/Cu(OH)₂ 나노와이어 (NWs) 전극을 합성하는 손쉬운 방법과 그 특성에 대해 보고한다. 제작된 SnO₂/Cu(OH)₂ NWs (-16 mA/cm²)는 -1.0 V (vs. RHE)에서 Cu(OH)₂ NWs (-6 mA/cm²) 대비 더 우수한 전기화학적 성능을 보였다. CO₂ 환원 성능을 확인해 보았을 때도 일산화탄소(CO), 포름산염 (HCOOH) 생성물에 대해 각각 29.72 %, 58.01 %의 높은 페러데이 효율 (FE)을 보였다. 본 연구는 CO₂ 배출로 인한 기후 변화에 대응하는 경제적이며 지속 가능한 방법을 제공할 뿐만 아니라, 전기화학적 CO₂ 환원용 전극 개발에 크게 기여할 것으로 예상된다.

• 한국수소및신에너지학회논문집
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• 제19권6호
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• pp.498-504
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• 2008

Metal-reducing bacterium, Geobacter sulfurreducens is available for mediator-less microbial fuel cell (MFC) because it has biological nanowires(pili) which transfer electrons to outside the cell. In this study, in the anode chamber of the MFC system using G. sulfurreducens, the concentrations of NaCl, sodium phosphate and sodium bicarbonate as electrolytes were mainly optimized for the generation of electricity from acetate. 0.4%(w/v) NaClO and 0.5M $H_2SO_4$ could be utilized for the sterilization of acrylic plates and proton exchange membrane (major construction materials of the MFC reactor), respectively. When NaCl concentration in anode phosphate buffer increased from 5 to 50 mM, power density increased from 6 to $20\;mW/m^2$. However, with increasing sodium phosphate buffer concentration from 5 to 50 mM, power density significantly decreased from 18 to $1\;mW/m^2$. Twenty-four mM sodium bicarbonate did not affect electricity generation as well as pH under 50 mM phosphate buffer condition. Optimized anode chamber of MFC using G. sulfurreducens generated relatively high power density ($20\;mW/m^2$) with the maximum coulombic efficiency (41.3%).