• 한국세라믹학회지
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• 제38권6호
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• pp.506-508
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• 2001

The ferrite plating with applying power ultrasound waves of 19.5 kHz and 600W enabled us to encapsulate entirely MnZn ferrite cores for transformers with Ni$\sub$x/Zn$\sub$y/Fe$\sub$3-x-y/O$_4$coating. Supplying a NH$_4$OH solution during the plating broke the limit of the solubility of Ni ions to ferrite-plated films. The electrical resistivity of the NiZn ferrite coating increased with increasing the Ni and Zn content, reaching 2.3${\times}$10$\^$5/Ωcm at the composition of Ni$\sub$0.24/Zn$\sub$0.30/Fe$\sub$2.46/O$_4$. The saturation magnetization was 540 emu/㎤. As a result, the MnZn ferrite cores were successfully encapsulated with the NiZn ferrite coatings for an insulation layer.

• 한국세라믹학회지
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• 제40권2호
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• pp.146-152
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• 2003

지구온난화의 주요 원인인 $CO_2$를 분해시키기 위하여 Ni-Zn 페라이트와 Mn-Zn 페라이트 코어 제조시 대량으로 배출되는 페라이트 폐기물을 이용하였다. 폐기물 페라이트와 페라이트 코어 완제품인 Ni-Zn 페라이트와 Mn-Zn 페라이트는 5% $H_2$/Ar과의 환원반응에서 14~16wt%가 환원되었다. 환원된 페라이트를 이용한 $CO_2$분해 반응에서는 세 종류의 페라이트 모두 약 11wt%에 해당하는 $CO_2$를 분해하였다. 이 반응에서 $CO_2$는 환원된 페라이트 중 Fe와 FeO치 산화에 의해 분해되었으며. 폐기물 페라이트의 경우 $CO_2$분해 반응 후 스피넬 결정상을 형성하였다. 대량으로 버려지는 폐기물 페라이트를 이용하여 저비용으로 $CO_2$분해가 가능한 폐기물 활용기술을 개발하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.898-901
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• 2006

본 논문에서는 저손실 Mn-Zn 페라이트의 제조공정과 첨가제가 코어의 자기적 특성에 미치는 영향을 조사하였다. 통신부품재료로 Mn-Zn 페라이트 개발에는 필요한 높은 포화자속밀도 및 투자율을 가진 고주파 특성이 양호하고 자기손실도 적은 재료의 필요하다. 따라서, Mn-Zn 페라이트의 고주파 자기 특성의 개선을 위해서는 결정입자의 소경화와 입자계층의 고저항화에 따른 와전류 손실의 억제 및 미세 구조의 균일화에 따른 히스테리시스 손실의 저감이 중요하다. 본 논문에서는 고성능, 저손실의 자심재료를 위해 Mn-Zn Ferrite에 $V_2O_5$와 $CaCo_3$를 첨가하였다. 조성은 MnO : ZnO : $Fe_2O_3$ = 21 : 10 : 69 mol%로 하였다. 이 시료를 $1250^{\circ}C$에서 3시간 소결하였다. 측정은 0.1MHz에서 초투자율을 측정하였으며, 전력손실은 50mT에서 100kHz 및 온도를 변화시켜 측정하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권2호
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• pp.61-66
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• 2003

The electromagnetic properties and thermal behavior of Mn-Zn ferrite cores used for the blocking filter in he Power Line Communication(PLC) application were investigated as the function of additives. The highest density and permeability of 4.98 g/㎤) and 8,221 respectively were obtained to the specimen with composition of MnO 24 mol%, ZnO 25 mol% and Fe$_2$O$_3$ 51 mol% added MnO$_3$ 400 ppm, SiO$_2$ 100 ppm and CaO 200 ppm since the uniform grains were organized and the microstructures were compacted through reduction of pores. The permeability was increased up to 13,904 as temperature of specimen increased to 11$0^{\circ}C$, however, it was decreased precipitously under 100 over 11$0^{\circ}C$. The exothermic behavior was observed in the frequency range from 1 kHz to 1 MHz that the maximum temperature of specimens became 102$^{\circ}C$ at 1 MHz. In the consequence, the Mn-Zn ferrite core developed by this research will maintain the stable electromagnetic properties since the temperature of ferrite core rose to 93$^{\circ}C$ in the range of 10 kHz to 450 kHz bandwidth qualified for PLC.

• 자원리싸이클링
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• 제8권4호
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• pp.45-56
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• 1999

본 연구의 목적은 불순물들을 다량 함유한 mill scale과 ferro-Mn을 정제과정을 거쳐 불순물들의 함량을 100 ppm 이하로 감소시킨 후 이들을 원료로 사용하여 Mn-Zn ferrite 원료분말을 기존의 고상반응법이 아닌 분무배소 방법에 의해 제조하는데 있다. 이를 위하여 본 연구에서는 정제된 원료용액을 분무배소시킴으로써 고상의 미세한 복합산화물 분말을 형성시키며, 생성된 분말을 효율적으로 포집할 수 있을 뿐 아니라 유해 생성기체를 중화시킬 수 있는 분무배소로 system을 개발하였다. 또한 정제된 원료 용액을 본 연구에서 개발된 분무배소로 내로 투입시킴으로써 Mn-ferrite 및 $Fe_{2}O_{3}$와 $Mn_{2}O_{3}$의 복합산화물 분말을 제조하였으며, 이때 각각의 조건 하에서 생성된 분말들에 대해 조성, 비표면적 및 입도 분포 등의 물리적, 화학적 특성을 조사하였다. 분무 배소법에 의해 생성된 원료분말에 ZnO 및 기타 첨가제를 정해진 조성으로 혼합시킨 후 성형 및 엄격하게 제어된 소결과정에 의해 Mn-Zn ferrite core를 제조하였다. 또한 제조된 core에 대하여 손실값, 초투자율, 잔류자속밀도, 항자력 및 포화자속밀도의 자기적 특성을 측정하였으며, 이 결과들을 바탕으로 Mn-Zn ferrite 원료 분말을 제조하기 위한 분무배소방법의 타당성을 확인하였다.

• KIEE International Transactions on Electrophysics and Applications
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• 제12C권4호
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• pp.220-224
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• 2002

The electromagnetic properties and thermal behavior of Mn-Zn ferrite cores for the blocking filter of PLC application were investigated as the function of additives. The highest density and permeability were 4.98 g/㎤ and 8,221, respectively and were obtained to the specimen with composition of MnO 24 mol%, ZnO 25 mol% and Fe$_2$O$_3$51 mol%, added MoO$_3$ of 400 ppm, SiO$_2$ of 100 ppm, and CaO of 200 ppm. The uniform grains were organized, and the microstructures were compacted due to reduction of pores in the specimen. The permeability was increased up to 13,904 as the temperature of specimen increased to 110。C. However, it was decreased precipitously under 100 over 110。C. The exothermic behavior was observed in the frequency range from 1 kHz to 1 MHz, and the maximum temperature of specimen was 102。C at 1 MHz. In the consequence, the Mn-Zn ferrite core developed in this research will maintain the stable electromagnetic properties since the temperature of ferrite core rose to 93 。C in the range of 100 kHz to 450 kHz bandwidth qualified for PLC. The blocking filters were designed for single phase and three phases using the in-line and non-contact core. The best attenuation ratios of -46.46 dB and -73.9 dB were measured in the range of 100 kHz to 450 kHz bandwidth, respectively.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.245-248
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• 2001

Nomura Kohsan Corp. is producing oxides, such as ZnMn$_2$O$_4$, ZnFe$_2$O$_4$, and ZnO, by burning the used dry manganese cells and by sorting out the remnant materials. It is possible to use the recycled materials of the spent dry batteries as the raw materials of deflection yoke cores. Making hish roasting temperature in the recycling system has an effect in reduction of the impurities. As a result, the loss of the cores using the recycled materials is lower. When using the recycled materials, it is required to add Mg (OH)$_2$. ZnO, and Fe$_2$O$_3$in order to rectify the composition of the MnMgZn ferrite for deflection yoke core applications. Furthermore, in order to disappear ZnMn$_2$O$_4$in the formation, it is necessary to control at higher calcining temperatures. The MnMgZn ferrite of using the recycled materials becomes Toss equivalent to the conventional material. TDK Corp. is manufacturing the deflection yoke cores from 1996 using the material recycled from the spent dry batteries.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.652-655
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• 2001

Power transformers are increasingly becoming more significant in the advancement of electronic equipment. A high-performance, low-cost core material is necessary in order th come up with power transformers in the smallest and lightest scale possible and with low power requirements. In this study, we added V$_2$O$_{5}$ and CaCo$_3$to Mn-Zn ferrite to produce a high-performance low-cost core material. The compositions used were MnO : ZnO : Fe$_2$O$_3$= 37 : 11 : 52 mol%. The materials were sintered at 125$0^{\circ}C$ for three hours. Initial permeability was measured at 0.1MHz. At 200mT, power loss was measured by changing the temperature at 25KHz, 50KHz, 100KHz. When we added 0.lwt% and 0.1%wt% of V$_2$O$_{5}$와 CaCo$_3$, respectively we obtained 405 405KW/㎥ at 200mT, 100KHz, 6$0^{\circ}C$. We tan reduce eddy current loss as a primary loss of high frequency by adding a small amount of V$_2$O$_{5}$와 CaCo$_3$. This reduces power loss in the power transformersormers

• 한국전기전자재료학회논문지
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• 제16권6호
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• pp.490-495
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• 2003

The electromagnetic properties and thermal behavior of Mn-Zn ferrite cores for the blocking filter of Power Line Communication(PLC) application were investigated as a function of additives. The highest density and permeability were 4.98 g/$\textrm{cm}^2$ and 8,221, respectively and were obtained to the specimen with composition of MnO 24 mol%, ZnO 25 mol% and Fe$_2$O$_3$ mol%, added MoO$_3$ of 400 ppm, SiO$_2$ of 100 ppm, and CaO of 200 ppm. The uniform grains were organized, and the microstructures were densified due to reduction of pores in the specimen. The permeability was increased up to 13,904 as the temperature of specimen increased to 110$^{\circ}C$. However, it was decreased precipitously under 100 over 110$^{\circ}C$. The exothermic behavior was observed in the frequency range from 1 kHz to 1 MHz, and the maximum temperature of specimen was 102$^{\circ}C$ at 1 MHz. In the consequence, the Mn-Zn ferrite core developed in this research will maintain the stable electromagnetic properties since the temperature of ferrite core rose to 93$^{\circ}C$ in the range of 100 kHz to 450 kHz bandwidth qualified for PLC. The blocking filters were designed for single phase and three phases using the in-line and non-contact core. The best attenuation ratios of -46.46 dB and -73.9 dB were measured in the range of 100 kHz to 450 kHz bandwidth, respectively.

• 한국자기학회지
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• 제9권3호
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• pp.149-153
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• 1999

SiO2-CaO-V2O5 3원계 첨가물을 함유한 Mn-Zn 페라이트 저손실의 주파수 및 온도 의존성에 대해 조사하고 주된 자기손실기구에 대해 고찰하였다. 연쇄고온합성법에 의해 MnO:ZnO:FeO=36:11:53mol% 조성의 페라이트를 제조하였다. 자기손실의 주파수 의존 결과로부터 저주파에서는 자기이력손실이 고주파에서는 와전류손실이 지배적임을 제시하였고, 고저항 첨가제에 의해 비저항이증가할수록 자기이력손실이 감소하였다. 순수 Mn-Zn 페라이트의 경우 자기 손실은 온도 증가에 따라 증가하였으나, 입계저항제가 첨가된 시편의 경우 와전류손실의 감소로 약 4$0^{\circ}C$에 서 자기손실의 최소치가 나타났다.