• Title, Summary, Keyword: $HoSi_2$

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Electrical Properties of Sintered $HoSi_2$ ($HoSi_2$소결체의 전기적 특성 연구)

  • 이우선;김형곤;김남오
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.10
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    • pp.792-795
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    • 2001
  • we present a electrical transport(resistivity, Hall effect) measurements in varying temperature ranges between 78K and 300K on HoSi$_2$ composites by hot-pressed sintering. It has been found that this sintered HoSi$_2$ has a orthorhombic structure, and lattices constant is a=9.8545$\AA$, b=7.7935$\AA$, c=7.8071$\AA$. The measured electrical resistivity is about 1.608$\Omega$ cm and carrier mobility is about 6.9$\times$10$^{1}$cm $^{2}$V.sec at low room temperature. The Hall effect shows a n-type conductivity in the sintered HoSi$_2$.

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Electrical properties of sintered $HoSi_2$ ($HoSi_2$ 소결체의 전기적 특성 연구)

  • Lee, Woo-Sun;Oh, Guem-Kon;Kim, Hyung-Gon
    • Proceedings of the KIEE Conference
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    • pp.1396-1398
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    • 2001
  • The $HoSi_2$ compounds prepared by codeposition of Si and Ho, and $HoSi_2$ by sintering method were investigated electrical and Hall effect. The crystal structure of samples showed a orthorhombic structure, and lattices constant is a=9.8545 $\AA$, b=7.7935 $\AA$, c=7.8071 $\AA$. Hall effect shows a n-type conductivity in the sintered $HoSi_2$. The electrical resistivity values was 1.608${\Omega}cm^{-1}$ and carrier mobility was $6.9{\times}10^1cm^2/V{\cdot}sec$ at low room temperature.

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Effects of DaeSiHo-Tang extract on Hypertension and Arterial Contraction (대시호탕(大柴胡湯)이 고혈압과 수축혈관에 미치는 영향)

  • Yeo Un-Hong;Jo Hak-Jun;Kim Ho-Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.6
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    • pp.1573-1579
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    • 2005
  • This study was undertaken to define the effect of DaeSiHo-Tang extract on the hypertension in spontaneous hypertensive rat and norepinephrine-induced arterial contraction in rabbit. Systolic blood pressure and blood velocity were significantly attenuated by administration of DaeSiHo-Tang extract. but blood flow and renin-angiotensin-aldosterone system unaffected by DaeSiHo-Tang extract. The relaxation effect of DaeSiHo-Tang extract was dependent on the presence of endothelium, showing that DaeSiHo-Tang extract-induced relaxation was not observed in the strips without endothelium. The endothelium-dependent relaxation induced by DaeSiHo-Tang extract was decreased by the pretreatment of $N{\omega}$-nitro-L-arginine or methylene blue, but it was not observed in the strips pretreated with indomethacin or tetraethylammonium chloride. When $Ca^{2+}$ was applied, the strips which were contracted by norepinephrine in a $Ca^{2+}$-free solution, arterial contraction was increased. But pre-treatment of DaeSiHo-Tang extract inhibited contractile response to $Ca^{2+}$. These results indicate that antihypertensive effect of DaeSiHo-Tang extract is due to descend arterial resistance by the arterial relaxation through the formation of nitric oxide in the vascular endothelial cells.

The Physical Characteristics and Preparation of $Mg_2SiO_4(La.Ho)$ Thermoluminescent Phosphor ($Mg_2SiO_4(La.Ho)$열형광체의 제작과 물리적 특성)

  • Noh, Kyung-Suk;Song, Jae-Heung;Koo, Hyo-Geun;Lee, Deog-Kyu
    • Journal of radiological science and technology
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    • v.20 no.1
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    • pp.65-69
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    • 1997
  • [ $Mg_2SiO_4(La.Ho)$ ] thermoluminescent phosphor was made by putting the $MgCl_2.6H_2O$ and $SiO_2$ and by doping the rare earth element of $LaCl_3.7H_2O$ and $HoCl_3$. The heating rate is $10^{\circ}C/sec$ for the thermoluminescent phosphor. Two peaks are found in the measured $Mg_2SiO_4(La.Ho)$ Tl glow curve at $152^{\circ}C$ and $205^{\circ}C$ when the heating rate is $5^{\circ}C/sec$. The peak value at $205^{\circ}C$ is the most sensitive to X-ray among the glow peaks. The activation energy of the main peak has been estimated by the peak shape method. The estimated activation energies for Ho and La are $0.52{\sim}1.77\;eV$ respectively.

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Annealing Effects of Tunneling Dielectrics Stacked $SiO_2/Si_3N_4$ Layers for Non-volatile Memory (비휘발성 메모리를 위한 $SiO_2/Si_3N_4$ 적층 구조를 갖는 터널링 절연막의 열처리 효과)

  • Kim, Min-Soo;Jung, Myung-Ho;Kim, Kwan-Su;Park, Goon-Ho;Jung, Jong-Wan;Chung, Hong-Bay;Cho, Won-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.128-129
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    • 2008
  • The annealing effects of $SiO_2/Si_3N_4$ stacked tunneling dielectrics were investigated. I-V characteristics of band gap engineered tunneling gate stacks consisted of $Si_3N_4/SiO_2/Si_3N_4$(NON), $SiO_2/Si_3N_4/SiO_2$(ONO) dielectrics were evaluated and compared with $SiO_2$ single layer using the MOS(Metal-Oxide-Semiconductor) capacitor structure. The leakage currents of engineered tunneling barriers (ONO, NON stacks) are lower than that of the conventional $SiO_2$ single layer at low electrical field. Meanwhile, the engineered tunneling barriers have larger tunneling current at high electrical field and improved electrical characteristics by annealing processes than $SiO_2$ layer.

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Growth of Ti on Si(111)-)-$7{\times}7$ Surface and the Formation of Epitaxial C54 $TiSi_2$ on Si(111) Substrate (Si(111)-$7{\times}7$ 면에서 Ti 성장과 C54 $TiSi_2$/Si(111) 정합 성장에 관하여)

  • Kun Ho Kim;In Ho Kim;Jeoung Ju Lee;Dong Ju Seo;Chi Kyu Choi;Sung Rak Hong;Soo Jeong Yang;Hyung Ho Park;Joong Hwan Lee
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.67-72
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    • 1992
  • The growth of Ti on Si(111)-$7{\times}7$ and the formation of epitaxial C54 $TiSi_2$ were investigated by using reflection high energy electron diffraction(RHEED) and high resolution transmission electron microscopy(HRTEM). Polycrystalline Ti layer is grown on the amorphous Ti-Si interlayer which is formed at the Ti/Si interface by Ti deposition on Si(111)-$7{\times}7$ at room temperature (RT). HRTEM lattice image and transmission electron diffraction(TED) showed that epitaxial C54 $TiSi_2$ grown on Si substrate with 160 ML of Ti on Si(111)-$7{\times}7$ surface at RT, followed by annealing at $750^{\circ}C$ for 10 min in UHV. Thin single crystal Si overlayer with [111] direction is grown on $TiSi_2$ surface when $TiSi_2$/Si(111) is annealed at ${\sim}900^{\circ}C$ in UHV, which was confirmed by Si(111)-$7{\times}7$ superstructure.

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Effect of heat treatment in $HfO_2$ as charge trap with engineered tunnel barrier for nonvolatile memory (비휘발성 메모리 적용을 위한 $SiO_2/Si_3N_4/SiO_2$ 다층 유전막과 $HfO_2$ 전하저장층 구조에서의 열처리 효과)

  • Park, Goon-Ho;Kim, Kwan-Su;Jung, Myung-Ho;Jung, Jong-Wan;Chung, Hong-Bay;Cho, Won-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.24-25
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    • 2008
  • The effect of heat treatment in $HfO_2$ as charge trap with $SiO_2/Si_3N_4/SiO_2$ as tunnel oxide layer in capacitors has been investigated. Rapid thermal annealing (RTA) were carried out at the temperature range of 600 - $900^{\circ}C$. It is found that all devices carried out heat treatment have large threshold voltage shift Especially, device performed heat treatment at $900^{\circ}C$ has been confirmed the largest memory window. Also, Threshold voltage shift of device used conventional $SiO_2$ as tunnel oxide layer was smaller than that with $SiO_2/Si_3N_4/SiO_2$.

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Reliability of Multiple Oxides Integrated with thin $HfSiO_x$ gate Dielectric on Thick $SiO_2$ Layers

  • Lee, Tae-Ho;Lee, B.H.;Kang, C.Y.;Choi, R.;Lee, Jack-C.
    • Journal of the Microelectronics and Packaging Society
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    • v.15 no.4
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    • pp.25-29
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    • 2008
  • Reliability and performance in metal gate/high-k device with multiple gate dielectrics were investigated. MOSFETs with a thin $HfSiO_x$ layer on a thermal Si02 dielectric as gate dielectrics exhibit excellent mobility and low interface trap density. However, the distribution of threshold voltages of $HfSiO_x/SiO_2$ stack devices were wider than those of $SiO_2$ and $HfSiO_x$ single layer devices due to the penetration of Hf and/or intermixing of $HfSiO_x$ with underlying $SiO_2$. The results of TZDB and SILC characteristics suggested that a certain portion of $HfSiO_x$ layer reacted with the underlying thick $SiO_2$ layer, which in turn affected the reliability characteristics.

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