• Title/Summary/Keyword: $Mg_2SiO_4$

Search Result 666, Processing Time 0.033 seconds

Fabrication of MgO(100)/$Si_3N_4/SiO_2/Si_3N_4$/Si Substrate for Pyroelectric IR Sensor (초전형 적외선 센서를 위한 MgO(100)/$Si_3N_4/SiO_2/Si_3N_4$/Si 기판 제작)

  • Kim, Sung-Woo;Sung, Se-Kyoung;Ryu, Jee-Youl;Choi, Woo-Chang;Choi, Hyek-Hwan;Lee, Myoung-Kyo;Kwon, Tae-Ha
    • Journal of Sensor Science and Technology
    • /
    • v.9 no.2
    • /
    • pp.90-95
    • /
    • 2000
  • The substrate for pyroelectric IR sensor which has orientation similar to MgO single crystal was fabricated by depositing the MgO thin film on $Si_3N_4/SiO_2/Si_3N_4$/Si. The MgO thin film was deposited by RF magnetron sputtering. The c-axis orientation of PLT thin film deposited on Pt/MgO(100)/$Si_3N_4/SiO_2/Si_3N_4$/Si substrate was investigated. The MgO thin film deposited at $500^{\circ}C$ at a gas pressure of 30 mTorr with RF power of 160 W exhibited a good a-axis orientation. The PLT thin films deposited on these substrates also exhibited c-axis orientation similar to the PLT thin films deposited on MgO single crystal substrate.

  • PDF

A study on Electrical and Diffusion Barrier Properties of MgO Formed on Surface as well as at the Interface Between Cu(Mg) Alloy and $SiO_2$ (Cu(Mg) alloy의 표면과 계면에서 형성된 MgO의 확산방지능력 및 표면에 형성된 MgO의 전기적 특성 연구)

  • Jo, Heung-Ryeol;Jo, Beom-Seok;Lee, Jae-Gap
    • Korean Journal of Materials Research
    • /
    • v.10 no.2
    • /
    • pp.160-165
    • /
    • 2000
  • We have investigated the electrical and diffusion barrier properties of MgO produced on the surface of Cu (Mg) alloy. Also the diffusion barrier property of the interfacial MgO between Cu alloy and $SiO_2$ has been examined. The results show that the $150\;{\AA}$-MgO layer on the surface remains stable up to $700^{\circ}C$, preventing the interdiffusion of C Cu and Si in Si/MgO/Cu(Mg) structure. It also has the breakdown voltage of 4.5V and leakage current density of $10^{-7}A/\textrm{cm}^2/$. In addition, the combined structure of $Si_3N4(100{\AA})/MgO(100{\AA})$ increases the breakdown voltage up to lOV and reduces the leakage current density to $8{\tiems}10^{-7}A/\textrm{cm}^2$. Furthermore, the interfacial MgO formed by the chemical reac­t tion of Mg and $SiO_2$ reduces the diffusion of copper into $SiO_2$ substrate. Consequently, Cu(Mg) alloy can be applied as a g gate electrode in TFT /LCDs, reducing the process steps.

  • PDF

Preparation and Luminescent Properties of (Zn1-xMgx)2SiO4:mn Phosphors ((Zn1-xMgx)2SiO4:mn 형광체의 제조와 발광특성)

  • Lee, Ji-Young;Yu, Il
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.22 no.5
    • /
    • pp.415-418
    • /
    • 2009
  • $Zn_{2}SiO_{4}$:Mn green phosphors doped with Mg for PDP were synthesized by solid state reaction method. $Zn_{2}SiO_{4}$:Mn, Mg phosphors with increasing Mg concentration were changed from Rhombohedral to Orthorhombic structure. Photoluminescence intensity of $Zn_{2}SiO_{4}$:Mn phosphors doped with Mg 0.5 mol was definitely higher than that of Mg non-doped sample. The enhanced luminescence with doping Mg in the $Zn_{2}SiO_{4}$:Mn phosphors was interpreted by the increase of energy transfer from host to Mn ions with substitution Mg for Zn in the $Zn_{2}SiO_{4}$:Mn host.

A Study of Fundamental Characteristics for $Mg_2SiO_4$ : Tb Phosphor ($Mg_2SiO_4$ : Tb 소자의 기본 특성에 관한 연구)

  • Park, Myeong-Hwan;Park, Chong-Sam;Kwon, Duk-Moon;Lee, Joon-Il
    • Journal of radiological science and technology
    • /
    • v.19 no.2
    • /
    • pp.79-83
    • /
    • 1996
  • The thermoluminescence(TL) response in changing annealing condition, triboluminescence, and darkroom temperature for $Mg_2SiO_4$:Tb phosphor are examined. The experimental results are summerized as follows : 1. The uniformity of TL intensity is better In the disinfected $Mg_2SiO_4$ : Tb than in contaminated one. 2. The triboluminescence of $Mg_2SiO_4$ : Tb is almost not detected even if numbers of $Mg_2SiO_4$ : Tb falling are increased. 3. The fading effect of $Mg_2SiO_4$ : Tb is scarcely affected by freezing room. The followings are resulted from the study. The disinfected $Mg_2SiO_4$ : Tb phosphor should be used in the dose measurement and the immediate reading for $Mg_2SiO_4$ : Tb after exposure is better. And if the reading is not immediately taken, a law darkroom temperature for $Mg_2SiO_4$ : Tb storage is recommended.

  • PDF

Effect of $CaTiO_3$Additions on Microwave Dielectric Properties in $BaWO_4$-$Mg_2$$SiO_4$Ceramics ($BaWO_4$-$Mg_2$$SiO_4$세라믹스의 $CaTiO_3$첨가에 따른 고주파 유전특성)

  • 박일환;김경용;김병호
    • Journal of the Korean Ceramic Society
    • /
    • v.38 no.3
    • /
    • pp.280-286
    • /
    • 2001
  • 10 이하의 저유전율을 갖는 (1-x)BaWO$_4$-xMg$_2$SiO$_4$(x=0.1~0.9) 세라믹스의 미세구조와 고주파 유전특성을 조사하였다. (1-x)BaWO$_4$-xMg$_2$SiO$_4$(x=0.1~0.9) 세라믹스는 정방정(tetragonal) 구조를 가진다. 0.1BaWO$_4$-0.9Mg$_2$SiO$_4$세라믹스는 BaWO$_4$$Mg_2$SiO$_4$의 상들이 공존하는 혼합상을 보였으며, $Mg_2$SiO$_4$가 이차사으로 형성된 것이 관찰되었다. 120$0^{\circ}C$~140$0^{\circ}C$에서 2시간 동안 소결된 (1-x)BaWO$_4$-xMg$_2$SiO$_4$(x=0.1~0.9) 세라믹스는 $\varepsilon$$_{r}$=6.37~8.21, Q.f=15000~99422 그리고 $ au$$_{f}$=73.9~48.9 ppm/$^{\circ}C$의 고주파 유전특성을 가졌다. $\tau$$_{f}$를 보정하기 위해, CaTiO$_3$(1,5 wt%)가 (1-x)BaWO$_4$-xMg$_2$SiO$_4$(x$\geq$0.9) 세라믹스에 첨가되었다. 135$0^{\circ}C$에서 2시간 동안 소결된 0.1BaWO$_4$-0.9Mg$_2$SiO$_4$+CaTiO$_3$(5 wt%) 세라믹스는 $\varepsilon$$_{r}$=7.3, Q.f=30532 그리고 $\tau$$_{f}$=-30 ppm/$^{\circ}C$의 고주파 유전특성을 얻었다. 얻었다.

  • PDF

Mechanical Properties and Fabrication of Nanostructured Mg2SiO4-MgAl2O4 Composites by High-Frequency Induction Heated Combustion (기계적 활성화된 분말로부터 고주파유도 가열 연소합성에 의한 나노구조 Mg2SiO4-MgAl2O4 복합재료 제조 및 기계적 특성)

  • Shon, In-Jin;Kang, Hyun-Su;Hong, Kyung-Tae;Doh, Jung-Mann;Yoon, Jin-Kook
    • Korean Journal of Metals and Materials
    • /
    • v.49 no.8
    • /
    • pp.614-618
    • /
    • 2011
  • Nanopowders of MgO, $Al_2O_3$ and $SiO_2$ were made by high energy ball milling. The rapid sintering of nanostructured $MgAl_2O_4-Mg_2SiO_4$ composites was investigated by a high-frequency induction heating sintering process. The advantage of this process is that it allows very quick densification to near theoretical density and inhibition of grain growth. Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties. As nanomaterials possess high strength, high hardness, excellent ductility and toughness, undoubtedly, more attention has been paid for the application of nanomaterials. Highly dense nanostructured $MgAl_2O_4-Mg_2SiO_4$ composites were produced with simultaneous application of 80MPa pressure and induced output current of total power capacity (15 kW) within 2min. The sintering behavior, gain size and mechanical properties of $MgAl_2O_4-Mg_2SiO_4$ composites were investigated.

Preparation and Luminescent properties of $(Zn_{1-x}Mg_x)_2SiO_4$:Mn phosphors ($(Zn_{1-x}Mg_x)_2SiO_4$:Mn 형광체의 제조와 발광특성)

  • Lee, Ji-Young;Yu, Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.11a
    • /
    • pp.392-393
    • /
    • 2007
  • PDP용 녹색 $Zn_2SiO_4$:Mn 형광체의 발광특성과 결정성을 향상시키기 위해 co-dopant로 Mg를 첨가한 $(Zn_{1-x}Mg_x)_2SiO_4$:Mn 형광체를 합성하였다. 합성된 형광체의 발광특성을 PL로 조사한 결과, $Zn_2SiO_4$:Mn 형광체는 Mg의 농도에 관계없이 530nm에서 녹색 발광을 하였고, Mg의 농도가 0.5 mol%일 때 가장 높은 발광세기가 나타났다. 이것은 Zn과 이온반경이 비슷한 Mg가 치환되어 모체에서의 Mn으로의 에너지 전이가 증가하여 발광세기가 증가한 것으로 생각된다.

  • PDF

The Study of $K_2O-MgO-Al_2O_3-SiO_2-MgF_2$ System in Fluro-phlogopite Synthesis. (불소운모 합성에 따른 $K_2O-MgO-Al_2O_3-SiO_2-MgF_2$계의 연구)

  • 송경근;오근호;김대웅
    • Journal of the Korean Ceramic Society
    • /
    • v.20 no.1
    • /
    • pp.37-42
    • /
    • 1983
  • An attempt was made to derive a possible synthetic mechanism of Fluoro-phlogopite (Mica, 4Mg.$Al_2O_3$.$6SiO_2$.$K_2O$.$2MgF_2$) The pevention of fluorine vaporization turned out to be the key in the synthesis of Mica in question.l Consequently the quinary system of Mica was seperately synthesized ; frist 4MgO.$Al_2O_3-6SiO_2$(ternary system) was sintered at 135$0^{\circ}C$ and $K_2O$ and $MgF_2$ were added and second 4MgO.$Al_2O_3-6SiO_2$.$K_2O$ (quarternary system) was heat-treated at 135$0^{\circ}C$ and $MgF_2$ was added. The ternary system resulted in Proto-enstatite Cordierite and Spinel phases while Forsterite and Leucite were shown in the quarternay system . In both methods Fluoro-phlogopite was systhesized but the solid state reactions to form Mica from the ternary system and the quarternary system were different. High temperature reactions in the formation of Mica were investigated employing XRD, DTA and SEM The study of the synthesis of Mica indirectly suggested a method of phase analysis of quinary system(MgO-$Al_2O_3-SiO_2-K_2O-MgF_2$) and quarternary system(MgO-$Al_2O_3-SiO_2-K_2O-MgF_2$) at various temperatures.

  • PDF

Effect of $CaTiO_3$Additions on the Microwave Dielectric Properties of $Mg_2$$SiO_4$-$ZnAl_2$$O_4$Ceramics with Low Dielectric Constant (저유전율을 갖는 $Mg_2$$SiO_4$-$ZnAl_2$$O_4$계 세라믹스의 $CaTiO_3$첨가에 따른 고주파 유전특성)

  • 박일환;김현학;김경용;김병호
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.13 no.12
    • /
    • pp.1017-1024
    • /
    • 2000
  • Effect of the microwave dielectric properties and the microstructure on a mole fraction(x=0.1~0.9) of (1-x)Mg$_2$SiO$_4$-xZnAl$_2$O$_4$ ceramics was investigated. When (1-x)Mg$_2$SiO$_4$-xZnAl$_2$O$_4$(x=0.1~0.9) ceramics were sintered at 130$0^{\circ}C$, 135$0^{\circ}C$ and 140$0^{\circ}C$ for 2hr, the microwave dielectric properties were obtained $\varepsilon$r=6.8~8.3, Q.f$_{0}$=36000~77600. On the other hand, the temperature coefficients of resonant frequency($\tau$$_{f}$) were obtained in the properties of -62ppm/$^{\circ}C$ to -49ppm/$^{\circ}C$. In order to adjust the temperature coefficient of resonant frequency($\tau$$_{f}$), CaTiO$_3$was added in (1-x)Mg$_2$SiO$_4$-xZnAl$_2$O$_4$ceramics. 0.7Mg$_2$SiO$_4$-0.2ZnAl$_2$O$_4$-0.1CaTiO$_3$ceramics sintered at 135$0^{\circ}C$ for 2hr showed the excellent microwave dielectric properties of $\varepsilon$r=7.7, Q.f$_{0}$=32000, and $\tau$$_{f}$=-7.9 ppm/$^{\circ}C$.EX>.>.EX>.

  • PDF

Growth and dissolution behavior of $CaO{\cdot}6Al_2O_3$ phase by reaction between alumina and silicate liquid phase (알루미나와 실리케이트 액상간의 반응에 따른 $CaO{\cdot}6Al_2O_3$ 상의 성장 및 용해 거동)

  • 백용균;박상엽
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.5 no.3
    • /
    • pp.291-298
    • /
    • 1995
  • Abstract The growth and dissolution behaviour of reaction phase was studied during dissolution reaction between sintered alumina and $CaMgSiO_4$ at $1600^{\circ}C$ for various times. The formation of $CaO{\cdot}6Al_2O_3$ an intermediate reaction phase, and $CaMgSiO_4$ spinel, the final reaction product were observed during dissolution reaction of alumina into $CaMgSiO_4$ liquid phase. The growth and dissolution shape of $CaO{\cdot}6Al_2O_3$, an intermediate phase, was quite different.

  • PDF