• 한국표면공학회지
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• 제56권4호
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• pp.227-232
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• 2023

In this study, complex admittance as a function of temperature and frequency was measured to analyze the important relaxation properties of lead scandium niobate, which is physically important, although it is not an environmentally friendly electrical and electronic material, including lead. Lead scandium niobate was synthesized by heat treating the solid oxide, and the conductance, susceptance and capacitance were measured as a function of temperature and frequency from the temperature dependence of the RLC circuit. The relaxation characteristics of lead scandium niobate were found to be affected by contributions such as grain size, grain boundary characteristics, space charge, and dipole arrangement. As the temperature rises, the maximum admittance and susceptance increase in one direction, but the resonance frequency decreases below the transition temperature but increases after the phase transition.

• 한국광학회지
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• 제1권2호
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• pp.149-154
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• 1990

$Tb^{3+}$이온을 첨가한 borosilicate 유리속에서 일어나는 에너지전달을 연구하기 위하여 $Tb^{3+}$이온의 농도에 따른 형광방출의 세기 및 $^5D_3$과 $^5D_4$ 준위의 형광수명시간을 측정.분석하였다. $Tb^{3+}$이온농도가 증가하면 cross-relaxation에 의해 $^5D_3$ 준위의 상태밀도가 줄어드는 대신에 $^5D_4$ 준위의 상태밀도가 증가했다. 그리고 이 상호작용은 전기 쌍극자-전기쌍극자 상호작용이며 임계작용거리는 13$\AA$이었다. 또 5D4 형광방출을 소광시키는 원인이 되는 $^5D_4$$\longrightarrow$$^5D_4$형의 에너지전달은 그 임계작용거리가 3.5$\AA$으로 나타났다.

• 전기화학회지
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• 제22권2호
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• pp.53-59
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• 2019

전해질의 미시 구조분석을 위해서는 이온-이온 및 이온-용매 상호작용을 이해하는 것이 매우 중요하다. 이 총설은 유전체 이완 분광법(Dielectric relaxation spectroscopy)의 기본 원리와, 이를 이용한 전해질 구조 연구 사례를 소개하고자 한다. 유전체 이완 분광법은 임피던스법의 일종으로서, 수십 GHz 수준의 높은 주파수 영역에 걸쳐 전해질의 유전 특성을 측정한다. 이를 통해, 유전체 이완 분광법은 전해질 내 존재하는 다양한 극성 화학 종, 즉, 쌍극자 모멘트(Dipole moment)를 갖는 자유 용매(Free solvent) 및 이온쌍(Ion pair)의 종류와 농도에 대한 정보를 제공한다. 유전체 이완 분광법이 제공하는 정보는 기존 분석 기법(적외선 분광법(Infrared), 라만 분광법(Raman) 및 핵자기 공명 분광법(Nuclear magnetic resonance) 등)이 제공하는 정보들과 상호보완적 관계에 있으며, 이러한 종합적 분석을 통해 전해질 구조에 관한 깊은 이해가 가능하다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.695-698
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• 2012

• Bulletin of the Korean Chemical Society
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• 제26권5호
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• pp.841-844
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• 2005

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3866-3869
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• 2010

• Bulletin of the Korean Chemical Society
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• 제30권3호
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• pp.731-734
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• 2009

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.228-230
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• 1993

In this paper, to investigate the activation energy, dipole moment, relaxation time, and so on related to charged particles more completely, it was applied numerical method of asymptotic estimation to separate single relaxation from TSC spectra with a complex relaxation. As a result, we could calculated the error of physical factors related to charged particles of specimen, more accurately.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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• pp.125-129
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• 1992

When relaxation time will be distributed, TSC observed in the experimental procedure was analysed by using a potential model having two equilibrium positions and equations of dielectric properties was derived. Calculation of distribution was made by matrix method and compared/confirmed values obtained by TSC and alternating current which have a correspondence with each other. In this measurement, distribution of activation energy and relaxation time was determined by TSC peak at around 147k/364 of which center is 10$\^$-4/ sec/10$\^$5/ sec respectively at room temperature and also obtained dielctric loss factor at the range of 10$\^$-7/-10$\^$5/Hz. It seems that low temperature peak is local dispersion and high temperature peak have a relation to dielectric transition of the material.

• Bulletin of the Korean Chemical Society
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• 제16권12호
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• pp.1184-1189
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• 1995

The rapid quenching dynamics of F center excitation by OH- defects in KCl crystals are investigated by monitoring ground state absorption bleach recovery, using a picosecond streak camera absorption spectrometer. F center absorption bleach in OH--doped crystals shows three distinguishable recovery components with the current temporal resolution, designated as slow, medium and fast components. The slow one is due to the normal relaxation process of F* centers as found in OH--free crystals. The others are consequent on energy transfer from electronically excited F centers to OH--vibrational levels. The fast component is a minor energy transfer process and resulting from the relaxation of somewhat distant, not the closest, associated pairs of F* and OH- defects. The energy transfer between widely separated F* and OH- defects opens up a recovery process via the medium component which is assisted by OH- librations, lattice vibrations and OH- dipole reorientations. The quenching behaviors of F* luminescence and photoionization by OH- are explained well by the relaxation process of the medium component.