• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.139-142
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• 1998

PLZT thin films were fabricated with different Zr/Ti ratios by pulsed laser deposition. PLZT films deposited on Pt/Ti/SiO$_2$/Si substrate. This PLZT thin films of 5000${\AA}$. thickness were crystallized at 600$^{\circ}C$, 200 mTorr O$_2$ press. 2/55/45 PLZT thin film showed a maximum dielectric constant value of $\varepsilon$$\_$r/=1500, and dielectric loss was 0.O$_3$. At 2/70/30 PLZT thin film, Coercive field and remnant polarization was respectively 19[kV/cm], 8[${\mu}$C/$\textrm{cm}^2$].

• Proceedings of the KOR-BRONCHOESO Conference
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• 2010.03a
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• pp.45-46
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• 2010

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.82-82
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• 1999

Ferroelectric materials are characterized by the existence of a spontaneous remnant polarization that can be switched between two stable states by an applied field. This phenomenon is known as ferroelectricity. The ferroelectricity can be utilized for nonvolatile memory application. Up to now 256K FRAM was successfully fabricated and sold in the memory market. This paper will briefly review the current statue of ferroelectric random access memory (FRAM) focusing on recent developments. In addition, the future prospects of FRAM will be addressed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.5-8
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• 1994

In this paper, Dielectric and strain properties of (1-x-y)PMN-yPT-xST Ceramics hale been investigated as a function of the amount of SrTiO$_3$(ST). The SrTiO$_3$ content is ranged from 0.01-0.05(wt%). As the amount of ST is increased, dielectric constant has a maximun value at 0.05 mol% composition. The Curie temperature is decreased linearly with increasing ST composition and Polarization properties have been investigated. Coercive field and remnant polarization has a maximum value at 0.01mo1% composiion.

• Electrical & Electronic Materials
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• v.7 no.5
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• pp.369-375
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• 1994

In this study, ferroelectric thin films of PZT with different Zr/Ti ratio were prepared by sol-get processing and annealed by rapid thermal annealing at >$500^{\circ}C$>$-700^{\circ}C$ for 10 sec. -1 min. Structures of the annealed films were examined by X-ray diffraction and SEM. Thin films of PZT with perovskite structure have been obtained by annealing at >$600^{\circ}C$ or above and for 20 seconds or longer. Maximum remnant polarization of 10.24.mu.C/cm$^{2}$ and minimum coercive field of 20.06 kV/cm were obtained from the 56/44 and 65/35 Zr/Ti composition films, respectively. Dielectric constant, .epsilon.$_{r}$ of 500-1300 and dielectric loss, tan .delta., of 0.01-0.035 were obtained from the films.s.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.279-281
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• 1996

This paper deals with the two stage surge protection device by using varistor and LC low pass filter. Recently varistor alone has been used with overvoltage protection devices for the AC power mains and has same problems associated with high remnant voltage and noise. In this work, in order to improve the cutoff performance of surge protection device, the lightning surge protection device having two stage hybrid circuit for an AC single phase mains was designed and fabricated. Operation characteristics and surge clamping performance of the surge protection device in an $8/20{\mu}s$ surge current are investigated. As a consequence, it is found that the proposed two stage surge protective device for AC power mains has a variety of advantages such as a smaller clamping voltage, high frequency noise reduction and large clamping capacity.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1106-1109
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• 1993

Ferroelectric thin films of PZT with differnt Zr/Ti ratio were prepared by sol-gel processing and annealed by rapid-thermal-annealing at $500^{\circ}C-700^{\circ}C$ for 10sec-1min. The structure of the annealed films were examined by X-ray diffraction and SEM. Maximum remnant polarization of 10.24 ${\mu}m/cm^2$ and coercive field of 70 KV/cm were obtained from hysteresis curve or the film.

• Transactions on Electrical and Electronic Materials
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• v.3 no.1
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• pp.42-45
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• 2002

Properties of lead zirconate titanate ferroelectric thin films prepared by rapid thermal annealing/direct insertion thermal annealing were investigated. The remnant polarization (Pr), saturation polarization (Ps), and coercive force (Ec) of typical samples annealed by rapid thermal annealing (RTA) are about 13.7 $\mu$ C/cm$^2$, 27.1 $\mu$C/cm$^2$, and 55.6 kV/cm, respectively. The dielectric constant of the sample is about 786, the dielectric loss tangent is about 2.4% at 1 kHz. Furthermore, ferroelectric, conduction, and piezoelectric properties of the thin films annealed by RTA process and the direct insertion thermal annealing (DITA) process were compared. The influence of temperature in the dry process on the above properties was also investigated.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.298-303
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• 2000

The 3 mol% yttria stabilized zirconia (3-Y PSZ) powder was heat treated at 50 0$^{\circ}C$ to evaporate the polymer binder and stabilize the tetragonal phase. The wear experiments were carried out on a ring-on-plate type reciprocating wear tester at selected temperatures with in the range room temperature to 600$^{\circ}C$ The results show that the heat treatment of powder decreases the wear rate due to the reduction of microcracks and pores in coatings and the stabilization of the tetragonal phase. Powder heat treatment enhanced the quality of the coating layer by removing remnant gases during coating process and the powder heat treatment at which tetragonal phase is stable diminished phase ratio of monoclinic. These two effects improved wear resistance characters.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.2
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• pp.132-140
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• 2006

Well-differentiated thyroid cancer is the most common endocrine malignancy with an increasing incidence. Most patients with well-differentiated thyroid caner have a favorable prognosis with high survival rate. While surgery and radioiodine therapy is sufficient treatment for the majority of patients with differentiated thyroid cancer, a minority of these patients experiences progressive, life-threatening growth and metastatic spread of the disease. Because there is no prospective controlled study to evaluate the differences of management of thyroid cancer, it is hard to choose the best treatment option. And there are still lots of controversies about the management of this disease, such as surgical extent, proper use of radioiodine for remnant ablation and therapy, use of rhTSH instead of withdrawal of thyroid hormone, long-term follow-up strategy, thyroglobulin as a tumor marker, etc. In this review, recent data related to these conflicting issues and recent advances in diagnosis, radioiodine therapy and long-term monitoring of well-differentiated thyroid cancer are summarized.