• Title/Summary/Keyword: gel materials

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A Study on Surface of BST Thin Films by Sol-Gel Methods (졸겔법으로 제작된 BST 박막의 구조적 특성)

  • 홍경진;민용기;조재철
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.377-380
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    • 2001
  • The BST thin films to composite (Ba$\sub$x/Sr$\sub$l-x/)TiO$_3$ using sol-gel method were fabricated on Pt/Ti/SiO$_2$/Si substrate. The thin film capacitor to be ferroelectric materials was investigated by structural and electrical properties. BST solution was composited by moi ratio, and then spin-coated (from 3 times to 5 times coating on Pt/SiO$_2$/Si substrate. Thickness of BST ceramics thin films are about 2600∼2800[${\AA}$] in 3 times deposition. The property of leakage current was stable when the applied voltage was 3[V]. Leakage current of 3 times coated BST thin film was 10$\^$-9/∼10$\^$-11/[A] at 0∼3[V].

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Electrochemical characteristic of CoOx ambigel electrode in various electrolyte for supercapacitor (Supercapacitor용 CoOx ambigel의 전해질에 따른 전기화학적 특성)

  • 이희우;김한주;김성호;박수길
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.749-752
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    • 2001
  • Very fine cobalt oxide xerogel and ambigel powder were prepared using a unique solution chemistry associated with the sol-gel process. The mesoporous structure of the initial gel is maintained by removing fluid under conditions where the capillary forces that result extraction are either low or no existent, are either low or nonexistent. Controlling both the pore and solid architecture on the nanoscale offers a strategy for the design of supercapacitor. The results materials determine by using electrode that mixed ketjen black and PVdF. But CoO$\_$x/ have the low voltage, so we experimente to change electrolyte and various concentration.

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CO Sensor Characteristics of ZnO powders by Sol-Gel methods (Sol-Gel법에 의한 ZnO 분말의 CO 센서 특성)

  • Park, Bo-Seok;Park, Jin-Seoung;Noh, Whyo-Sub
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.821-825
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    • 2002
  • ZnO thick films by Sol-Gel processing were investigated electrics, optics and the sensing characteristics of CO gas. Using the znic acetate dihydrate and acetylaceton (AcAc) as a chelating agent, stable ZnO sol was synthesized. ZnO phase was crystallized through the heat-treatment at $70^{\circ}C$ for 4hrs and influenced the sensing characteristics of the electrics and CO gas by uniform particle distributions not related particle size. The samples on the alumina substrate by thick films were investigated the properties of electrics and the effect of sensing. The sensitivity was so excellent in the sample of the heat-treatment at $600^{\circ}C$ for 12hrs and good in the heat-treatment for 1hrs generally. Crystallization and volatilization of organic materials according to the change of heating treatment temperature of thick films were analyzed by TG-DTA, XRD and mirostructure of thick films were observed by SEM.

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The rapid thermal annealing effects and its application to electron devices of Sol-Gel derived ferroelectric PZT thin films (졸-겔법으로 형성한 강유전체 PZT박막의 고온 단시간 열처리효과 및 전자 디바이스에의 응용)

  • 김광호
    • Electrical & Electronic Materials
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    • v.7 no.2
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    • pp.152-156
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    • 1994
  • The rapid thermal annealing effects of Sol-Gel derived ferroelectric PZT thin films were investigated. It was found that rapid thermal annealing(RTA) of spin coated thin films on silicon typically >$800^{\circ}C$ for about 1 min. was changed to the perovskite phase. Rapid thermally annealed films recorded maximum remanent polarization of about 5 .mu.C/cm$^{2}$, coercive field of around 30kV/cm. The switching time for polarization reversal was about 220ns. The films of RTA process showed smooth surface, and high breakdown voltages of over 1 MV/cm and resistivity of $1{\times}{10^12}$ .ohm.cm at 1 MV/cm. It was verified that the polarization reversal of the PZT film was varied partially with applying the multiple short pulse.

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Preparation and Properties of Sol-Gel Processed Lead Lanthanum Titanate Thin

  • Kim, Hyun-Hoo;Lee, Jung-Geun
    • Transactions on Electrical and Electronic Materials
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    • v.1 no.1
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    • pp.17-21
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    • 2000
  • In order to investigate the dependence of a content in lead lanthanum titanate (PLT) films and heat treatment, sol-gel process has been used. Four types of PLT thin films with the chemical formula, Pb$\_$1-x/ La$\_$x/Ti$\_$1-x/4/O$_3$(X=18, 21, 24 and 28 mole %) have been fabricated on Pt/Ti/SiO$_2$/Si multi-layers and ITO/glass substrates, The post-annealing temperature in the range of 400~700 $\^{C}$ is applied for the formation of perovskite structure in PLT films. The structureal, electrical and optical properties of PLT film with the addition of La content are estimated. The films orientation and surface structure of films are studied by XRD (X-ray diffraction) and SEM(scanning electron microscopy). The P-E hysteresis loop become narrower with increasing La content. The average transmittance of the films is about 80%.

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Preparation of $Li_2O-ZrO_2-P_2O_5-SiO_2$ based Glassy Solid Electrolytes by Sol-Gel Process and Their Ionic Conduction (솔-젤법에 의한 $Li_2O-ZrO_2-P_2O_5-SiO_2$계 유리 고체전해질의 제조와 그의 이온전도성)

  • 박강석;김기원;강은태
    • Journal of the Korean Ceramic Society
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    • v.31 no.6
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    • pp.660-670
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    • 1994
  • Transparent, crack-free dried gel monoliths with a composition of LiZr1.5Si2P2O12.5 have been synthesized by the low temperature polymerization of the Sol-Gel technique using metal alkoxides as starting materials. After initial reaction (20~40 min), each metal alkoxide closely paralleled each other during the hydrolysis reactions. The safe drying conditions of gels with no creaks the control of the shrinkage rate. The gels converted into the glass by heat treatment at 75$0^{\circ}C$. FTIR data indicated that the gels were phase separated into silicarich and phosphate-rich regions with the lithium. XRD results showed the formation of crystalline LiH2PO4. The gels dried at 15$0^{\circ}C$ or fired at 75$0^{\circ}C$ contained the residual water. The high ionic conductivity at room temperature for these gels was attributed to the motion of protons.

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Effect of Additives on Mechanical Properties of Alumina Bushing Fabricated by Gel-Casting

  • Hwang, Kwang-Taek;Cheong, Deock-Soo
    • Journal of the Korean Ceramic Society
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    • v.46 no.6
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    • pp.653-656
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    • 2009
  • Alumina bushing used for manufacturing glass fiber was fabricated by gel-casting which can fabricate complex forms. When solid loading is increased, density was increased and shrinkage and absorption were decreased. The sample loading with 57 vol% solid was optimum for alumina suspension, which showed the best physical properties. The cast sample was sintered at $1550{^{\circ}C}$ for two hours with sintering additive, $Y_2O_3$. The result showed that the alumina bushing with $Y_2O_3$ sintering additive has a density of 98%, shrinkage of 11% and bending strength of 196 kg/$cm^2$.

Opto-Electrical Study of Sol-Gel Derived Antimony Doped Tin Oxide Films on Glass

  • De, Arijit
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.1
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    • pp.5-9
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    • 2015
  • Optical and electrical properties were studied for Antimony doped tin oxide thin films from precursors containing 10, 30, 50, and 70 atom% of Sb deposited on bare sodalime silica, barrier layer coated sodalime silica, and pure silica glass substrates by sol-gel spinning technique. The direct band gaps were found to vary from 3.13~4.12 eV when measured in the hv range of 2.5~5.0 eV, and varied from 4.22~5.08 eV when measured in the range of 4.0~7.0 eV. Indirect band gap values were in the range of 2.35~3.11 eV. Blue shift of band gap with respect to bulk band gap and Moss-Burstein shift were observed. Physical thickness of the films decreased with the increase in % Sb. Resistivity of the films deposited on SLS substrate was in the order of $10^{-2}$ ohm cm. Sheet resistance of the films deposited on barrier layer coated soda lime silica glass substrate was found to be relatively less.

Characteristics of ZnO Films Deposited on Poly 3C-SiC Buffer Layer by Sol-Gel Method

  • Phan, Duy-Thach;Chung, Gwiy-Sang
    • Transactions on Electrical and Electronic Materials
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    • v.12 no.3
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    • pp.102-105
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    • 2011
  • This work describes the characteristics of zinc oxide (ZnO) thin films formed on a polycrystalline (poly) 3C-SiC buffer layer using a sol-gel process. The deposited ZnO films were characterized using X-ray diffraction, scanning electron microscopy, and photoluminescence (PL) spectra. ZnO thin films grown on the poly 3C-SiC buffer layer had a nanoparticle structure and porous film. The effects of post-annealing on ZnO film were also studied. The PL spectra at room temperature confirmed the crystal quality and optical properties of ZnO thin films formed on the 3C-SiC buffer layer were improved due to close lattice mismatch in the ZnO/3C-SiC interface.

Study on Sol-Gel Prepared Phosphosilicate Glass-Ceramic For Low Temperature Phosphorus Diffusion into Silicon

  • Kim, Young-Sig
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.2
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    • pp.32-36
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    • 2001
  • A new solid source for low temperature diffusion into silicon was developed. The source wafer consists of an “active” compound, which is sol-gel prepared phosphosilicate glass-ceramics containing 56% P$_2$O$\sub$5/, embedded in a skeletal foam-like, inert substrate. Phosphorus diffusion from the new solid sources at low temperatures (800-875$^{\circ}C$) produced reprodecible sheet resistances and shallow junctions. From a series of one hour doping runs, the life time of the phosphosilicate source was determined to be over 40 hours. The effective diffusion coefficient of phosphorus into silicon and the corresponding activation energy at 850$^{\circ}C$ were determined to be 7.5${\times}$10$\^$-15/ $\textrm{cm}^2$/sec and ∼3.9 eV, respectively.

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