• Title/Summary/Keyword: Growth properties

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Effects of Deposition Temperature on the Properties of InN Thin Films Grown by Radio-frequency Reactive Magnetron Sputtering (증착 온도가 RF 반응성 마그네트론 스퍼터링법으로 성장된 InN 박막의 특성에 미치는 영향)

  • Cho, Shin-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.10
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    • pp.808-813
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    • 2009
  • Indium nitride thin films were deposited by the radio-frequency reactive magnetron sputtering method. The indium target was sputtered by the mixture flow ratio of $N_2$ to Ar, 9:1. The effects of growth temperature on the structural, optical, and electrical properties of the films were investigated. With increasing the growth temperature, the crystallinity of the films was improved, and the crystalline size was increased. The energy bandgap for the film grown at $25^{\circ}C$ was 3.63 eV, and the bandgap showed an increasing tendency on the growth temperature. The carrier concentration, Hall mobility and electrical resistivity of the films depended significantly on the growth temperature and the maximum Hall mobility of $32.3\;cm^2$/Vsec was observed for the film grown at $400^{\circ}C$.

Growth and Electronic Properties of Ag Overlayers on Stepped Pt(211) Surface

  • 김유권;김정원;김세훈
    • Bulletin of the Korean Chemical Society
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    • v.17 no.12
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    • pp.1154-1157
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    • 1996
  • The growth and electronic properties of ultrathin silver films deposited onto Pt(211) surface were studied using Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and x-ray photoelectron spectroscopy. The AES and LEED results indicate that the silver grows by a layer by layer growth followed by three dimensional islands growth. The XPS results show that the Ag 3d core-level binding energy of Ag overlayers on Pt(211) shifts toward lower binding energy relative to the bulk value at lower Ag coverage. This negative binding energy shift of the Ag 3d core level is explained by the reduced coordination number of the overlayer atoms and the resulting initial state band narrowing effect suggested by Wertheim and Citrin [Phys. Rev. Lett. 1978, 41, 1425].

Synthesis and Characterization of MoO3 Nano Particle by Controlling Various Growth Conditions in Solution Combustion Method

  • Namhun Kwon;Seyoung Lee;Jaeseok Roh;Kun-Jae Lee
    • Archives of Metallurgy and Materials
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    • v.66 no.4
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    • pp.991-995
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    • 2021
  • In this paper, synthesize MoO3 particles with various particle properties by control growth influence factors was mainly studied. The experimental conditions were established in molar ratio of Mo:urea and pH levels. The plate-type of MoO3 particles were formed without proceeding any established conditions, but the rod-shape particles were formed by adjusting molar ratio of Mo:urea. Also, different ranges of the particle size were formed by adjusting experimental conditions. Through the results, it was confirmed that particles with a size in the range of 300 ~ 400 nm were obtained by adjusting precursor concentration and the micrometer size of particles were formed by increase pH levels. The properties of the particles formed accordingly by setting various factors that can affect the growth process of MoO3 particle was analyzed as variables and the particle growth behavior was also observed.

Realization of the Growth and Behavior of a Artificial Life based on User′s Act (사용자 행동에 기반한 인공생명체의 성장과 반응 구현)

  • Chung, Jin-Wook;Kim, Do-Wan;Kwon, Min-Su;Kang, Hoon
    • Proceedings of the IEEK Conference
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    • 2003.07d
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    • pp.1303-1306
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    • 2003
  • In this paper, In this paper, we modeled a virtual life(VL) that react to the user's action according to its own behavioral characteristics and grows itself. We established some conditions with which such a VL is designed. Genetic Algorithm is used for the growth process that changes the VL's properties. In this process, the parameter values of the VL's properties are encoded as one chromosome, and the GA operations change this chromosome. The VL's reaction to the user's action is determined by these properties as well as the general expectation of each reaction. These properties are evaluated through 5 fitness measures so as to deal with multi-objective criteria. Here, we present the simulation of the growth process, and show some experimental results.

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Effect of Fully and Semi Austempering Treament on the Fatigue Properties of Ductile Cast Iron (완전 및 부분 오스템퍼링 처리가 구상흑연주철의 피로특성에 미치는 영향)

  • Lim Bok-kyu;Hwang Jung-gak;Kim Dong-Youl;Kim Min-gun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.3 s.234
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    • pp.462-469
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    • 2005
  • Single phase bainite structure which is obtained by the conventional austempering treatment reduces the ductility of ductile cast iron. Because of the reduction of ductility it is possible to worsen the fatigue properties. Therefore, semi austempered ductile iron which is treated from ${\alpha}+{\gamma}$ is prepared to investigate the static strength and fatigue properties in comparison with fully austempered ductile iron (is treated from ${\gamma}$). In spite of semi austempered ductile iron shows the $86{\%}$ increase of ductility. Also, semi austempered ductile iron shows the higher fatigue limit and lower fatigue crack growth rate as compared with fully austempered ductile iron. By the fractographical analysis, it is revealed that the ferrite obtained by semi austempering process brings about the plastic deformation(ductile striation) of crack tip and gives the prior path of crack propagation. The relatively low crack growth rate in semi austempered specimen is caused by above fractographical reasons.

Characterization and Electrical Properties in (YNS)BCO Oxides by Rod-type Seeded Melt Growth Process

  • Kim, So-Jung;Park, Jong-Kuk;Lee, Sang-Gyo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.243-243
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    • 2007
  • We have studied the electrical properties and microstructure of $(Y_{0.5}Nd_{0.25}Sm_{0.25})Ba_2Cu_3O_y[(YNS)-123]$ Oxides by rod-type seeded melt growth process(RSMG) in air atmosphere. Rod-type $NdBa_2Cu_3O_y${Nd-123) seed crystals made a extrusion process method, were used for achieving the ab-plane alignment having large grains perpendicular to the center of (YNS)-123 samples. The observations using SEM and TEM micrographs of the melt-textured (YNS)-123 samples revealed that the nonsuperconducting $(Y_{0.5}Nd_{0.25}Sm_{0.25})Ba_2Cu_3O_y[(YNS)-211]$ inclusions are uniformly distributed in the superconducting matrix. The microstructure and electrical properties were investigated by XRD, SEM, TEM and DC SQUID magnetometer. The sample showed a sharp superconducting transition at 90 K. The magnetization values of the (YNS)-123 sample exhibited the enhanced electrical properties, compared with $YBa_2Cu_3O_y$(Y-123) sample.

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Reassessment of the Growth Properties of Mycelium among Cordyceps pruinosa Isolates According to Cultivation Conditions (배양조건에 따른 붉은자루동충하초 균주 간의 균사생장 특성 재평가)

  • Kim, Jun Young;Kwon, Hyuk Woo;Sung, Gi-Ho;Choi, Hyung-Kyoon;Sung, Jae-Mo;Kim, Seong Hwan
    • The Korean Journal of Mycology
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    • v.41 no.4
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    • pp.231-235
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    • 2013
  • To obtain basic data for the better use of Cordyceps pruinosa we reassessed the effect of different medium, culture method, pH, and carbon and nitrogen sources on the mycelial growth properties of four C. pruinosa isolates. The growth of mycelia differed among the four isolates depending on medium type and cultivation days. Among the tested 8 kinds of solid media, the four isolates grew well on PDA and MMMA(mushroom minimal medium agar). While, among the tested 8 kinds of liquid media, all the isolates grew well in SDYM(Sabourand's dextrose yeast extract medium). The isolates also grew well in the SDYM with pH from 4.0 to 9.5 without any inhibition. One isolate could best grow at pH 8 to 9.5. Regarding the ability of utilizing carbon source, the difference of mycelia growth among the isolates was the most with xylose. Regarding nitrogen source, three isolates could utilize urea which is new fact in this species. These results provide new points on the growth properties of the fungal mycelium which has not been explored before. Overall, this reassessed study concluded that it is necessary to check in advance the growth properties of mycelium when a new isolate of C. pruinosa is expected to be used for application.