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한국전기전자재료학회> 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.)> 자기전기복합체의 비공진 및 공진 상태에서의 자기전기 결합 특성 평가 방법

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자기전기복합체의 비공진 및 공진 상태에서의 자기전기 결합 특성 평가 방법

Demonstration of Magnetoelectric Coupling Measurement at Off-Resonance and Resonance Conditions in Magnetoelectric Composites

Deepak Rajaram Patil , 류정호 ( Jungho Ryu )
  • : 한국전기전자재료학회
  • : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권4호
  • : 연속간행물
  • : 2022년 07월
  • : 333-341(9pages)
전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.)

DOI


목차

1. INTRODUCTION
2. EXPERIMENTAL PROCEDURE
3. RESULTS AND DISCUSSION
4. CONCLUSIONS
ORCID
감사의 글
REFERENCES

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초록 보기

자기전기복합체(magnetoelectric, ME compositie)는 자왜재료와 압전재료의 결합현상을 이용하는 재료로서 지난 20여 년간 이론적, 실험적으로 많은 연구가 진행되어 왔다. 자기전기복합체의 출력특성은 구성하는 소재, 계면층, 복합체의 형상, 자기장하 진동모드 등의 많은 구성요소의 최적화를 통하여 급속히 향상되고 있다. 하지만 자기전기복합체의 자기전기 결합 특성 평가는 대부분의 연구들에서 구체적인 방법을 제시하지 않아 어떻게 측정한 것인지가 불명확한 경우가 많다. 본 논문에서는 자기전기복합체의 비공진, 공진상황에서 자기전기 전압계수를 어떻게 측정할 수 있는지에 대한 자세한 방법을 소개한다. 평가를 위한 샘플로서 대칭적인 구조를 가지는 Gelfenol/PMN-PZT/Gelfenol 자기전기복합체를 제조하였다. 압전 재료로는 이방성의 (011) 32 모드의 PMN-PZT 압전 단결정과 자왜재료로는 Galfenol 합금을 사용하여 에폭시로 접착하였다. 컴퓨터 인터페이스로 자동화된 자기전기 전압특성 측정 시스템의 구성을 우선 설명하고, 자기전기 결합특성의 측정 방법을 단계별로 설명한다. 본 튜토리얼 논문에서는 자기전기결합 특성과 특성평가방법을 이해하고자 하는 연구자들에게 도움이 될 수 있는 평가방법의 원리와 절차를 제공하고자 하였다.
Magnetoelectric (ME) composites are comprised of magnetostrictive and piezoelectric phases. Lots of theoretical and experimental works have been done on ME composites in the last couple of decades. The output performance of ME composites has been enhanced by optimizing the constituent phases, interface layer, dimensions of the ME composites, different operating modes, etc. However, the detailed information about the characterization of ME coupling in ME composites is not provided yet. Therefore, in this tutorial paper, we are giving an insight into the details of measurements of ME voltage coefficient of ME composites both at off-resonance and resonance conditions. A symmetric type Gelfenol/PMN-PZT/Gelfenol ME composites were fabricated by sandwiching (011) 32-mode PMN-PZT single crystal between two Galfenol plates by epoxy bonding are used for the example of ME coupling measurement. The details about the experimental setup used for the measurement of ME voltage coefficient are provided. Furthermore, a step-by-step measurement of ME voltage coefficient using computerized program is demonstrated. We believe the present experimental measurement details can help readers to understand the concept of ME coupling and its analysis.

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간행물정보

  • : 공학분야  > 전기공학
  • : KCI등재
  • :
  • : 격월
  • : 1226-7945
  • : 2288-3258
  • : 학술지
  • : 연속간행물
  • : 1988-2022
  • : 4661


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35권5호(2022년 09월) 수록논문
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1결함제어를 통한 열전 반도체 연구 동향

저자 : 민유호 ( Yuho Min )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 419-430 (12 pages)

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Defects in solids play a vital role on thermoelectric properties through the direct impacts of electronic band structure and electron/phonon transports, which can improve the electronic and thermal properties of a given thermoelectric semiconductor. Defects in semiconductors can be divided into four different types depending on their geometric dimensions, and thus understanding the effects on thermoelectric properties of each type is of a vital importance. This paper reviews the recent advances in the various thermoelectric semiconductors through defect engineering focusing on the charge carrier and phonon behaviors. First, we clarify and summarize each type of defects in thermoelectric semiconductors. Then, we review the recent achievements in thermoelectric properties by applying defect engineering when introducing defects into semiconductor lattices. This paper ends with a brief discussion on the challenges and future directions of defect engineering in the thermoelectric field.

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2강유전 세라믹의 전기장 인가에 따른 in situ X-선 회절 실험

저자 : 최진산 ( Jin San Choi ) , 김태헌 ( Tae Heon Kim ) , 안창원 ( Chang Won Ahn )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 431-438 (8 pages)

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기능성 소재연구에서 in situ 분석 기법은 외부 자극 (전기장, 자기장, 빛, 등) 또는 주변 환경 (온도, 습도, 압력, 등)과 같이 주어진 자극에 의해 소재의 물리적 특성이 어떻게 활성화/진화되는지 분석하는데 있어서 매우 중요하다. 특히, 전기장 인가에 따른 in situ X-선 회절(XRD) 실험은 다양한 강유전체, 압전체, 전왜 재료의 외부 전기장 인가에 따른 전기-기계적 반응의 기본 원리를 이해하기 위해 광범위하게 활용되었다. 본 튜토리얼 논문에서는 일반 실험실 규모의 XRD 장비를 이용하여 전기장 인가에 따른 in situ XRD 분석의 기본 원리/핵심 개념을 간략하게 소개한다. In situ XRD 측정법은 외부 전기장을 인가하여 구동되는 다양한 전기-기계 재료의 구조적 변형을 체계적으로 식별/모니터링하는 데 매우 유용할 것으로 기대한다.


In functional materials, in situ experimental techniques as a function of external stimulus (e.g., electric field, magnetic field, light, etc.) or changes in ambient environments (e.g., temperature, humidity, pressure, etc.) are highly essential for analyzing how the physical properties of target materials are activated/evolved by the given stimulation. In particular, in situ electric-field-dependent X-ray diffraction (XRD) measurements have been extensively utilized for understanding the underlying mechanisms of the emerging electromechanical responses to external electric field in various ferroelectric, piezoelectric, and electrostrictive materials. This tutorial article briefly introduces basic principles/key concepts of in situ electric-field-dependent XRD analysis using a lab-scale XRD machine. We anticipate that the in situ XRD method provides a practical tool to systematically identify/monitor a structural modification of various electromechanical materials driven by applying an external electric field.

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3레이저 기반 플라즈모닉 어닐링을 통한 은 나노입자 자가 생성 및 소결 공정과 이를 활용한 메탈메쉬 전극 기반 투명 웨어러블 히터

저자 : 황윤식 ( Yun Sik Hwang ) , 남의연 ( Ui Yeon Nam ) , 김연욱 ( Yeon Uk Kim ) , 우유미 ( Yu Mi Woo ) , 허재찬 ( Jae Chan Heo ) , 박정환 ( Jung Hwan Park )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 439-444 (6 pages)

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Laser-induced plasmonic sintering of metal nanoparticles (NPs) is a promising technology to fabricate flexible conducting electrodes, since it provides instantaneous, simple, and scalable manufacturing strategies without requiring costly facilities and complex processes. However, the metal NPs are quite expensive because complicated synthesis procedures are needed to achieve long-term reliability with regard to chemical deterioration and NP aggregation. Herein, we report laser-induced Ag NP self-generation and sequential sintering process based on low-cost Ag organometallic material for demonstrating highquality microelectrodes. Upon the irradiation of laser with 532 nm wavelength, pre-baked Ag organometallic film coated on a transparent polyimide substrate was transformed into a high-performance Ag conductor (resistivity of 2.2 × 10-4 Ω·cm). To verify the practical usefulness of the technology, we successfully demonstrated a wearable transparent heater by using Ag-mesh transparent electrodes, which exhibited a high transmittance of 80% and low sheet resistance of 7 Ω/square.

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4PZT-PZN 세라믹의 미세구조가 압전 특성 및 TCC 거동에 미치는 영향

저자 : 서인태 ( Intae Seo ) , 최용수 ( Yongsu Choi ) , 조유리 ( Yuri Cho ) , 강형원 ( Hyung-won Kang ) , 김강산 ( Kang San Kim ) , 천채일 ( Chae Il Cheon ) , 한승호 ( Seung Ho Han )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 445-451 (7 pages)

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Ultrasonic sensor is suitable as a next-generation autonomous driving assist device because its lower price compared to that of other sensors and its sensing stability in the external environment. Although Pb(Zr, Ti)O3 (PZT)-relaxor ferroelectric system has excellent piezoelectric properties, the change in capacitance is large in the daily operating temperature range due to the low phase transition temperature. Recently, many studies have been conducted to improve the temperature stability of ferroelectric ceramics by controlling the grain size and crystal structure, so it is necessary to study the effect of the grain size on the piezoelectric properties and the temperature stability of PZT-relaxor ferroelectric system. In this study, the piezoelectric properties, phase transition temperature, and temperature coefficient of capacitance (TCC) of 0.9 Pb(Zr1-xTix)O3-0.1 Pb(Zn1/3Nb2/3)O3 (PZTx-PZN) ceramics with various grain sizes were investigated. PZTx-PZN ceramics with larger grain size showed higher piezoelectric properties and temperature stability, and are expected to be suitable for ultrasonic devices in the future.

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5플래시메모리소자의 구조에 대한 열적 데이터 삭제 효율성 비교

저자 : 김유정 ( You-jeong Kim ) , 이승은 ( Seung-eun Lee ) , 이광선 ( Khwang-sun Lee ) , 박준영 ( Jun-young Park )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 452-458 (7 pages)

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The electro-thermal erasing (ETE) configuration utilizes Joule heating intentionally generated at word-line (WL). The elevated temperature by heat physically removes stored electrons permanently within a very short time. Though the ETE configuration is a promising next generation NAND flash memory candidate, a consideration of power efficiency and erasing speed with respect to device structure and its scaling has not yet been demonstrated. In this context, based on 3-dimensional (3-D) thermal simulations, this paper discusses the impact of device structure and scaling on ETE efficiency. The results are used to produce guidelines for ETEs that will have lower power consumption and faster speed.

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6IoT를 사용한 센서 네트워크 기반의 실시간 토양 습도 모니터링

저자 : 김경헌 ( Kyeong Heon Kim ) , 김희동 ( Hee-dong Kim )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 459-465 (7 pages)

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This paper reports a method to use a wireless sensor network deployed in the field to real-time monitor soil moisture, warning when the moisture level reaches a specific value, and wirelessly controlling an additional device (LED or water supply system, etc.). In addition, we report all processes related to wireless irrigation system, including field deployment of sensors, real-time monitoring using a smartphone, data calibration, and control of additional devices deployed in the field by smartphone. A commercially available open-source Internet of Things (IoT) platform, NodeMCU, was used, which was combined with a 9V battery, LED and soil humidity sensor to be integrated into a portable prototype. The IoT-based soil humidity sensor prototype deployed in the field was installed next to a tree for on-site demonstration for the measurement of soil humidity in real-time for about 30 hours, and the measured data was successfully transmitted to a smartphone via Wifi. The measurement data were automatically transmitted via e-mail in the form of a text file, stored on the web, followed by analyses and calibrations. The user can check the humidity of the soil real-time through a personal smartphone. When the humidity of a soil reached a specific value, an additional device, an LED device, placed in the field was successfully controlled through the smartphone. This LED can be easily replaced by other electronic devices such as water supplies, which can also be controlled by smartphones. These results show that farmers can not only monitor the condition of the field real-time through a sensor monitoring system manufactured simply at a low cost but also control additional devices such as irrigation facilities from a distance, thereby reducing unnecessary energy consumption and helping improve agricultural productivity.

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7빛의 밝기가 일정한 교류 구동 LED 조명기술

저자 : 이동원 ( Dong Won Lee ) , 안호명 ( Ho-myoung Ahn ) , 김병철 ( Byungcheul Kim )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 466-470 (5 pages)

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In order to widely disseminate LED lighting, LED lighting technology that directly uses AC commercial power has been recently introduced. AC powered LED lighting technology has a problem in that the light brightness of the LED changes because the voltage applied to the LED and the current flowing through the LED continuously change. In this study, when the LED current is greater than the design current, the current control signal generated by the controller is supplied to the current source to supply only the design current to the LED by increasing the voltage drop at the current source. If it is smaller than the design current, the controller is adjusted so that the current is supplied only to the LED without a voltage drop in the current source. It can be seen that the higher the maximum rectified voltage, the faster the lighting time of the LED light emitting block is, so that the power factor of the LED lighting is improved. The LED lighting technology proposed in this study enables LED lighting with constant light brightness, reduced power consumption, and long lifetime.

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8매개변수 평가법을 이용한 압전재료의 재료물성 최적화 연구 Part I. 다결정 PZT 세라믹스

저자 : 신호용 ( Ho-yong Shin ) , 이호용 ( Ho-yong Lee ) , 홍일곡 ( Il-gok Hong ) , 김종호 ( Jong-ho Kim ) , 임종인 ( Jong-in Im )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 471-479 (9 pages)

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Recently, piezoelectric devices, such as ultrasonic surgery, ultrasonic atomizer, and ultrasonic speaker, are analyzed and designed by finite element simulation methods. However, the discrepancy between the design and the experiment results of the device typically occurs due to the inaccuracy of the piezoelectric material properties. To improve the simulation accuracy, the material properties of the PZT ceramics were better refined using parameter estimation method. The material parameters are elastic stiffness cEij and piezoelectric constant eij of PZT ceramics. The impedance curve characteristics for the LTE mode of PZT ceramics were calculated. The mismatch between the simulation and the experimental data were compared and minimized by a least square method. Finally, the simulated impedance data were compared with the experimental data for the various vibration modes of PZT ceramics and the optimized material properties of PZT ceramics were verified. To further verify the accuracy, this method was also applied to piezoelectric PMN-PT single crystals.

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9진공인터럽터의 내전압 성능 향상을 위한 전류컨디셔닝 기법 연구

저자 : 차영광 ( Young-kwang Cha ) , 이일회 ( Il-hoi Lee ) , 전기범 ( Ki-beom Jeon ) , 장지훈 ( Ji-hoon Jang ) , 주흥진 ( Heung-jin Ju )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 480-487 (8 pages)

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As a process to improve the insulation performance of VIs (Vacuum Interrupters), AC voltage conditioning is generally adopted by many manufacturers. Although the insulation performance is enhanced easily with AC Voltage conditioning, it has limitations when high recovery voltage is required due to high voltage rate or capacitive current switching. In particular, impurities such as oxides segregated on the electrode surface can be removed not by the energy level of the voltage conditioning but by the higher energy level achieved by the current conditioning process In this article, the current conditioning was carried out in various conditions and its validity was examined. The current conditioning was processed by changing the amplitude of applied current, arc time, the number of tests, and frequency. The insulation performance and the status of contact surface were checked as well. We concluded that as the applied charge quantity and the conditioning coverage area increase, the conditioning effect is much higher.

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10듀얼 마그네트론 스퍼터링 법으로 제조된 Pd-Doped Carbon 박막의 물리적 특성에서 Pd 타겟 전력의 영향에 대한 연구

저자 : 최영철 ( Young-chul Choi ) , 박용섭 ( Yong Seob Park )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 5호 발행 연도 : 2022 페이지 : pp. 488-493 (6 pages)

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Generally, diamond-like carbon films (a-C:H, DLC) have been shown to have a low coefficient of friction, a high hardness and a low wear rate. Pd-doped C thin film was fabricated using a dual magnetron sputtering with two targets of graphite and palladium. Graphite target RF power was fixed and palladium target RF power was varied. The structural, physical, and surface properties of the deposited thin film were investigated, and the correlation among these properties was examined. The doping ratio of Pd increased as the RF power increased, and the surface roughness of the thin film decreased somewhat as the RF power increased. In addition, the hardness value of the thin film increased, and the adhesive strength was improved. It was confirmed that the value of the contact angle indicating the surface energy increases as the RF power increases. It was concluded that the increase in RF power contributed to the improvement of the physical properties of Pd-doped C thin film.

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1Volatile Memristor-Based Artificial Spiking Neurons for Bioinspired Computing

저자 : Soon Joo Yoon , Yoon Kyeung Lee

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 311-321 (11 pages)

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The report reviews recent research efforts in demonstrating a computing system whose operation principle mimics the dynamics of biological neurons. The temporal variation of the membrane potential of neurons is one of the key features that contribute to the information processing in the brain. We first summarize the neuron models that explain the experimentally observed change in the membrane potential. The function of ion channels is briefly introduced to understand such change from the molecular viewpoint. Dedicated circuits that can simulate the neuronal dynamics have been developed to reproduce the charging and discharging dynamics of neurons depending on the input ionic current from presynaptic neurons. Key elements include volatile memristors that can undergo volatile resistance switching depending on the voltage bias. This behavior called the threshold switching has been utilized to reproduce the spikes observed in the biological neurons. Various types of threshold switch have been applied in a different configuration in the hardware demonstration of neurons. Recent studies revealed that the memristor-based circuits could provide energy and space efficient options for the demonstration of neurons using the innate physical properties of materials compared to the options demonstrated with the conventional complementary metal-oxidesemiconductors (CMOS).

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2유전체를 활용한 초고속 에너지 충/방전 소자 기술

저자 : 최현수 ( Hyunsu Choi ) , 류정호 ( Jungho Ryu ) , 윤운하 ( Woon-ha Yoon ) , 황건태 ( Geon-tae Hwang )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 322-332 (11 pages)

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Energy storage capacitors based on dielectric ceramics with superior polarization properties and dielectric constant can provide much higher output power density due to their very fast energy charging/discharging rates, which are particularly suitable for operating pulsed-power devices. For an outstanding energy storage performance of dielectric capacitor, a large recoverable energy density could be derived by introducing a slim polarization-electric field hysteresis loop into dielectric materials by various technical approaches. Many research teams have explored various dielectric capacitor technologies to demonstrate high output power density and ultrafast charging/discharging behavior. This article reviews the recent research progress in high-performance dielectric capacitors for pulsed-power electronic applications.

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3자기전기복합체의 비공진 및 공진 상태에서의 자기전기 결합 특성 평가 방법

저자 : Deepak Rajaram Patil , 류정호 ( Jungho Ryu )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 333-341 (9 pages)

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자기전기복합체(magnetoelectric, ME compositie)는 자왜재료와 압전재료의 결합현상을 이용하는 재료로서 지난 20여 년간 이론적, 실험적으로 많은 연구가 진행되어 왔다. 자기전기복합체의 출력특성은 구성하는 소재, 계면층, 복합체의 형상, 자기장하 진동모드 등의 많은 구성요소의 최적화를 통하여 급속히 향상되고 있다. 하지만 자기전기복합체의 자기전기 결합 특성 평가는 대부분의 연구들에서 구체적인 방법을 제시하지 않아 어떻게 측정한 것인지가 불명확한 경우가 많다. 본 논문에서는 자기전기복합체의 비공진, 공진상황에서 자기전기 전압계수를 어떻게 측정할 수 있는지에 대한 자세한 방법을 소개한다. 평가를 위한 샘플로서 대칭적인 구조를 가지는 Gelfenol/PMN-PZT/Gelfenol 자기전기복합체를 제조하였다. 압전 재료로는 이방성의 (011) 32 모드의 PMN-PZT 압전 단결정과 자왜재료로는 Galfenol 합금을 사용하여 에폭시로 접착하였다. 컴퓨터 인터페이스로 자동화된 자기전기 전압특성 측정 시스템의 구성을 우선 설명하고, 자기전기 결합특성의 측정 방법을 단계별로 설명한다. 본 튜토리얼 논문에서는 자기전기결합 특성과 특성평가방법을 이해하고자 하는 연구자들에게 도움이 될 수 있는 평가방법의 원리와 절차를 제공하고자 하였다.

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4마이크로미터 단위 화학 반응 관찰 및 분석을 위한 미세 유량 제어 장치의 순환구조 제작 연구

저자 : 장원준 ( Wonjun Jang ) , 이남종 ( Namjong Lee ) , 정다운 ( Dawoon Jung ) , 김홍석 ( Hong-seok Kim ) , 정승찬 ( Seung Chan Jung ) , 한재희 ( Jae-hee Han )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 342-347 (6 pages)

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In-situ analyzation and detection of real-time chemical reactions can be a significant part in interpreting the underlying mechanism in very reactive chemical reactions. To do this, first we have designed a microfluidic device (MFD) pattern for observation of synthesis of hierarchical nanostructures based on graphene oxide (GO), conjugating the well-known coupling reaction by which the solution of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-mediated coupling is enhanced in the presence of n-hydroxysuccinimide (NHS) to make amide bonding, hereafter called as the EDC coupling. Then, we have manufactured microfluidic devices with multiple tens of micrometer-sized channels that can circulate those nanomaterials to be chemically reacted in the channels. These microfluidic devices were made by negative photo lithography and soft lithography. We showed the possibility of using Raman spectroscopy to reveal the basic mechanism of the energy storage applications.

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5Resistive Switching Effects of Zinc Silicate for Nonvolatile Memory Applications

저자 : Minho Im , Jisoo Kim , Kyoungwan Park , Junghyun Sok

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 348-352 (5 pages)

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Resistive switching behaviors of a co-sputtered zinc silicate thin film (ZnO and SiO2 targets) have been investigated. We fabricated an Ag/ZnSiOx/highly doped n-type Si substrate device by using an RF magnetron sputter system. X-ray diffraction pattern (XRD) indicated that the Zn2SiO4 was formed by a post annealing process. A unique morphology was observed by scanning electron microscope (SEM) and atomic force microscope (AFM). As a result of annealing process, 50 nm sized nano clusters were formed spontaneously in 200~300 nm sized grains. The device showed a unipolar resistive switching process. The average value of the ratio of the resistance change between the high resistance state (HRS) and the low resistance state (LRS) was about 106 when the readout voltage (0.5 V) was achieved. Resistance ratio is not degraded during 50 switching cycles. The conduction mechanisms were explained by using Ohmic conduction for the LRS and Schottky emission for the HRS.

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6가스절연개폐장치의 스페이서 내장형 전자식 변압기의 설계 및 제작

저자 : 임승현 ( Seung-hyun Lim ) , 김남훈 ( Nam-Hoon Kim ) , 김동언 ( Dong-eon Kim ) , 김선규 ( Seon-gyu Kim ) , 길경석 ( Gyung-suk Kil )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 353-358 (6 pages)

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Bulky iron-core potential transformers (PT) are installed in a tank of gas insulated switchgears (GIS) for a system voltage measurement in power substations. In this paper, we studied an electronic voltage transformer (EVT) embedded in a spacer for miniaturization, eco-friendliness, and performance improvement of GIS. The prototype EVT consists of a capacitive probe (CP) that can be embedded in a spacer and a voltage Follower with a high input and a low output impedance. The CP was fabricated in the form of a Flexible-PCB to acquire the insulation performance and to withstand vibration and shock during operation. Voltage ratio of the prototype EVT is about 42,270, and the frequency bandwidth of -3 dB ranges from 0.33 Hz to 3.9 MHz. The voltage ratio error evaluated at about 6%, 12% and 18% of the rated voltage of 170 kV was 0.32%, and the phase error was 12.9 minutes. These results were within the accuracy for the class 0.5 specified in IEC 60044-7 and satisfy even in ranges from 80% to 120% of the rated voltage. If the prototype EVT replaces the conventional iron-core potential transformer, it is expected that the height of the GIS could be reduced by 11% and the amount of SF6 will be reduced by at least 10%.

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7트립티센 기반의 트리페닐아민 전자-주게 분자 합성 및 특성 분석

저자 : 류영준 ( Youngjun Ryu ) , 안병관 ( Byeong-kwan An )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 359-365 (7 pages)

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The development of efficient electron donor (or hole-transporting) molecules that can be used in various optoelectronic device fields is highly demanded. In this work, a novel class of triptycene-based three-dimensional (3D) triphenylamine (TI-TPA) derivatives with different end substituents was designed and prepared for transparent electron donor materials. Owing to the rigid 3D triptycene framework, the obtained TI-TPA derivatives had an amorphous morphology with high thermal decomposition temperature. The oxidation potential of these TI-TPA derivatives decreased as the electron donating strength of the end substituent increased. Among TI-TPA derivatives, TI-TPA-OMe exhibited the highest HOMO level (-5.31 eV) which is similar to that of Spiro-OMeTAD (-5.22 eV). In addition, TI-TPA-OMe was found to form a strong charge transfer complex with the triptycene-based acceptor TI-BQ, leading to a new absorption band at around 640 nm. These results can be applied for developing efficient electron donor materials that can mimic the advantages of the spiro-linked structure and TPA units of Spiro-OMeTAD.

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8유기태양전지용 안트라퀴논 기반 전자 받게 분자의 특성 분석

저자 : 현창석 ( Chang-seok Hyun ) , 안병관 ( Byeong-kwan An )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 366-371 (6 pages)

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Recently many efforts have been made to develop a novel class of non-fullerene electron acceptor materials for highperformance organic solar cells. In this work, anthraquinone derivatives, TMAQ and THAQ, were prepared and their availability as electron acceptor materials for organic solar cells were investigated in terms of optical, thermal, electrochemical properties, and solar cell devices. Compared to TMAQ, a significant bathochromic shift of absorption band was observed for THAQ owing to intramolecular hydrogen-bond-assisted CT interactions. Thanks to the fused aromatic ring structure and benzoquinone unit, both TMAQ and THAQ exhibited a high thermal stability and an efficient electron reduction process. In particular, the intramolecular O-H---O=C hydrogen bond of THAQ plays an important role in improving the thermal stability and electron reduction properties. In the P3HT:acceptor solar cell system, THAQ-based devices had more than ca. 6 times higher power conversion efficiency than TMAQ -based devices. These results serve as a guide for developing high-efficient anthraquinonebased electron acceptor materials.

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9유한요소법에 의한 ZnO 바리스터 동작 시 발생되는 열폭주 현상 해석

저자 : 장경욱 ( Kyung-uk Jang )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 372-376 (5 pages)

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Since the ZnO varistor is a semiconductor device, the internal thermal distribution during the varistor operation is recognized as an important factor in the performance and deterioration of the varistor. For an optimal varistor structure design, the thermal runaway phenomenon during the varistor operation was interpreted using the Comsol 5.2 analysis program by a finite element analysis. The maximum temperature of the center measured in the cross section of the ZnO varistor was confirmed to increase as the temperature moved from the lower electrode to the center towards the upper electrode up to 572.6 K. The electrodes are thinned so that the influence of the Schottky barrier is not great. The heat gradient balance is determined to be improved when the electrode of the hybrid form is introduced. The thickness, density, pore distribution, impurity uniformity, and particle size of the ZnO varistor are required, and it is determined that the pyrolysis gradient will be improved regardless of the electrode thickness. When these results are applied to design the ZnO varistor, the optimal structure of the ZnO varistor can be obtained.

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10다공성 철 분말을 이용한 열전지용 열원 적합성 연구

저자 : 김지연 ( Ji Youn Kim ) , 윤현기 ( Hyun Ki Yoon ) , 임채남 ( Chae Nam Im ) , 조장현 ( Jang-hyeon Cho )

발행기관 : 한국전기전자재료학회 간행물 : 전기전자재료학회논문지(J. Korean Inst. Electr. Electron. Mater. Eng.) 35권 4호 발행 연도 : 2022 페이지 : pp. 377-385 (9 pages)

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Thermal batteries are specialized as primary reserve batteries that operate when the internal heat source is ignited and the produced heat (450~550oC) melts the initially insulating salt into highly conductive eutectic electrolyte. The heat source is composed of Fe powder and KClO4 with different mass ratios and is inserted in-between the cells (stacks) to allow homogeneous heat transfer and ensure complete melting of the electrolyte. An ideal heat source has following criteria to satisfy: sufficient mechanical durability for stacking, appropriate heat calories, ease of combustion by an igniter, stable combustion rate, and modest peak temperature. To satisfy the aforementioned requirements, Fe powder must have high surface area and porosity to increase the reaction rate. Herein, the hydrothermal and spray drying synthesis techniques for Fe powder samples are employed to investigate the physicochemical properties of Fe powder samples and their applicability as a heat source constituent. The direct comparison with the state-of-the-art Fe powder is made to confirm the validity of synthesized products. Finally, the actual batteries were made with the synthesized iron powder samples to examine their performances during the battery operation.

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