• 한국세라믹학회지
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• 제46권2호
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• pp.155-160
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• 2009

The reliability could be one of the essential properties for multilayer ceramic capacitor (MLCC) using in various electronic devices and the concentration and mobility of oxygen vacancy would play important role in the reliability. To investigate the migration behavior of oxygen vacancies, thermally stimulated depolarization current (TSDC) is adopted. In dielectric material of X5R MLCC, the TSD-Current peak observed around 150$^{\circ}C$ and 200$^{\circ}C$ which represented the migration of oxygen vacancy. Substituting Yttrium for Dysprosium in X5R MLCC showed higher migration activation energy and lower TSD current density.

• 대한전기학회논문지
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• 제39권4호
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• pp.357-363
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• 1990

A thermally stimulated current measurement using a temperature gradient (TG-TSC) has been applied to the study of dipolar depolarization in polymers. It has been clarified that theoretical analysis of TG-TSC in the initial rise region corresponds with the experimental results. We conclude that the experimental results on a cross-linked polyethy-lene (XLPE) film can be explained using the above relation and that the charasteristics obtained from the above theoretical analysis can be used for ascertaining the presence of a constant temperature gradient in a film.

• 센서학회지
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• 제29권1호
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• pp.59-62
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• 2020

Currently, increasing attention is being paid to relaxor-based ferroelectric single crystals in photoacoustic images, especially for high-end applications. Among the crystals are (1-x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PMN-100xPT) single crystals located near their morphotropic phase boundary (x = 0.30-0.35) because of their ultrahigh piezoelectric and electromechanical coupling properties. The alternating current poling (ACP) treatment, rather than the conventional direct current poling treatment, has recently been spotlighted due to its effectiveness in enhancing the piezoelectric properties. So far, it has been suggested that the enhanced piezoelectricity originates from either a domain miniaturization to nanodomains or from an electric-field-induced monoclinic symmetry. In this study, we demonstrate by thermally stimulated depolarization current measurements that the effect of ACP is too complex to be explained using a single mechanism and that the proposed electric-field-induced monoclinic symmetry is unlikely to exist.

• 한국재료학회지
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• 제12권8호
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• pp.613-616
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• 2002

The polarization properties of $BaTiO_3$ were investigated by using thermally stimulated depolarization current (TSDC) technique. Two peaks were observed at about 400 K (peak A) and 435 K (peak B) from TSDC spectra obtained from the temperature range of 280-500 K. Peak A shows a sharp decrease of TSDC due to extinction of spontaneous polarization above the phase transition temperature of $BaTiO_3$. The values of activation energy of peak A and peak B were calculated to be 0.70 eV and 0.87 eV respectively. From the results of TSDC measurement with a variation of polarizing electric field strength, we found that saturation of total current of TSDC was started from 3kV/cm. However, the amount of total current of TSDC was not affected by the variation of polarizing time.

• 한국안광학회지
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• 제3권1호
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• pp.269-277
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• 1998

$Li_2B_4O_7$의 완화현상은 이온 깡총뛰기에 의한 것과, 공간전하에 의한 완화현상의 두 가지 종류가 나타나며 이들의 완화시간은 실온 이상에서 모두 $10^2sec$보다 짧은 것으로 보고되었다. 지금까지 논의되지 않은 매우 낮은 주파수 (mHz 혹은 Hz)에서 나타나는 완화현상을 관찰하기 위하여 $30{\sim}500^{\circ}C$ 온도영역에서 TSDC(Thermally Stimulated Depolarization Current) 특성에 관한 실험과 사각형 파의 바이어스 전압을 인가하였을 때의 유전특성 조사에 의하여 이온 및 전자 trap에 의한 완화특성을 논의하였다. TSDC 조사를 통하여 $Li_2B_4O_7$의 TSDC 전류곡선이 두 개의 anomaly를 갖고 있는 것으로 나타났다. TSDC 에서 나타난 anomaly는 공간전하보다 수천배나 더 긴 완화시간을 갖고 있는 것으로 밝혀졌으며 이 중 저온 쪽의 anomaly는 공간전하 층에 수입된 전자들이 양의 공간전하 층에 trap 되어 공간전하의 재 분포를 방해하는 역할을 하여 trap 되어 있던 전자와 이온이 서로 분리되면서 공간전하의 재 분포가 이루어지는 전도기구에 기인하는 것으로 여겨진다. 또한 고온쪽의 anomaly는 음의 전하운반자가 전극에 흡착되어 나타나는 완화 mechanism으로 생각된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1989년도 춘계학술대회 논문집
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• pp.101-104
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• 1989

Thermal Electet of the Zinc Oxide varistor has been studied in the temperature range of -130~200[$^{\circ}C$] and the electric field of 6[kV/m]. It appears that there are four peaks of thermally stimulated current; $\alpha$, $\beta$, ${\gamma}$ and $\delta$ spectra appearing at the temperature range of 160, 130, 20 and -30[$^{\circ}C$], respectively. It seems that the origin of $\alpha$, $\beta$, ${\gamma}$ and $\delta$ peaks are associated with the depolarization of donor ions in the depletion layer, the detrapping of trapped electron in the surface, the detrapping of trapped electron in the donor level and the detrapping of trapped electron between grain and intergranular, respectively.

• 대한전기학회논문지
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• 제34권4호
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• pp.144-152
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• 1985

This paper temperature gradient thermally stimulated surface potentian (TG-TSSP) in measurements are applied to the study of the polarity of trapped and ionic carriers in cross-linked polyethylene (XLPE) filsm. In the thermally stimulated current in uniform temperature (TSC) of XLPE five peaks appear as indicated of the A B C D and E. In this paper A (at about -120$^{\circ}C$) D (at about 70$^{\circ}C$) and E (at about 110$^{\circ}C$) peaks are investigated. A peak is due to the biassing voltage and biassing temperature. Appear in to the glass transition temperature territory and caused in to the polarization of dipole. D peak is due to the depolarization of ionic space charge and E peak due to the detrapping of carriers injected from the electrodes. TG-TSSP and TSSP are measured to study the polarity of ionic carrier (D peak). In the unsatureated region of ionic space charge polarization, TG-TSSP is lower than TSSP during the initial stage of heating. Result of the experiment for E peak, TG-TSSP is higher than TSSP during the initial stage of heating and these results do not depend on the polarity of biassing voltage, and E peak is concerned with positive carriers (Holes).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.489-491
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• 1987

It has been shown that the thermally stimulated current technique can be one of the most powerful methods for evaluating the electrical properties. An unstretched $\alpha$-form specimen of corona-charged, 50[${\mu}m$],t Polyvinylidene Fluoride shows four TSC peaks designated $\delta}$, $\gamma$, $\beta$ and $\alpha$ in assending order of temperature in temperature range $-100{\sim}200^{\circ}C$. The $\delta$, $\gamma$ peaks may be attributed to the dipolar depolarization in the amorphous regions and $\beta$, $\alpha$ peaks are associated with the detrap from trapped carriers in the crystalline regions.

• 한국안전학회지
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• 제11권2호
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• pp.60-66
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• 1996

In order to look into the internal structure and electrical properties of insulating Silicone rubbers added reinforcing fillers ; Silica(0-140 phr ), and to examine the behavior of charged particles, and the properties of thermally stimulated current (TSC) are investigated, respectively. From the TSC which are formed by applying the electric field of 2~5 ㎸/mm to specimen at temperature range from -150 to $270^{\circ}C$, the results arp as following. In the case of non-filled specimen, four peaks of $\delta$, $\gamma$ , $\beta$ and u are obtained at the temperature of $-120^{\circ}C$, $-60^{\circ}C$, $20^{\circ}C$ and $130^{\circ}C$, respectively and the case of filled specimen, three peaks of $\delta$, ${\alpha}_2$ and ${\alpha}_1$ are observed at the temperature of of $-120^{\circ}C$, $80^{\circ}C$ and $130^{\circ}C$, respectively. The origins of these peaks are that, the $\delta$ peak seems to the result from the contribution of side chain methyl radical, and the $\beta$ peak from the depolarization of space charge polarization owing to added imputity during during manufacturing specimens, and the $\beta$ peak from the orientation of $Si-CH_3$dipole, and the ${\alpha}_2$ near the temperature of $130^{\circ}C$ from carboxyl acid that is formed by the thermal oxidation of high temperature.

• Elastomers and Composites
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• 제21권2호
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• pp.121-128
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• 1986

Studies has been carried out on the characteristics of thermally stimulated current for polypropylene in the temperature range of $293[^{\circ}K]{\sim}403[^{\circ}K]$. The main peak observed at $366[^{\circ}K]$, as may be $\beta$ peak in conventional nomination, is believed to be depolarization current originated from the relaxation of "CO" group in monomer structure. The activation energy for the observed peak has been concluded to be in the range of $0.6{\sim}0.7[(eV]$ at $360[^{\circ}K]$ by the initial rise method. Furthermore, the initial density of carriers were calculated about $10^{22}/m^3$