• 제목/요약/키워드: Lattice materials

검색결과 786건 처리시간 0.031초

열간등방가압 공정을 통한 P형 Bi0.5Sb1.5Te3.0 소결체의 격자 열전도도 감소 및 열전 특성 향상 (Enhancement of Thermoelectric Performance in Spark Plasma Sintered p-Type Bi0.5Sb1.5Te3.0 Compound via Hot Isostatic Pressing (HIP) Induced Reduction of Lattice Thermal Conductivity)

  • 정수호;우예진;김경태;조승기
    • 한국분말재료학회지
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    • 제30권2호
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    • pp.123-129
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    • 2023

  • High-temperature and high-pressure post-processing applied to sintered thermoelectric materials can create nanoscale defects, thereby enhancing their thermoelectric performance. Here, we investigate the effect of hot isostatic pressing (HIP) as a post-processing treatment on the thermoelectric properties of p-type Bi0.5Sb1.5Te3.0 compounds sintered via spark plasma sintering. The sample post-processed via HIP maintains its electronic transport properties despite the reduced microstructural texturing. Moreover, lattice thermal conductivity is significantly reduced owing to activated phonon scattering, which can be attributed to the nanoscale defects created during HIP, resulting in an ~18% increase in peak zT value, which reaches ~1.43 at 100℃. This study validates that HIP enhances the thermoelectric performance by controlling the thermal transport without having any detrimental effects on the electronic transport properties of thermoelectric materials.

  • https://doi.org/10.4150/KPMI.2023.30.2.123 인용 PDF

${BF^+}_2$ 이온 주입된 실리콘 시료의 격자손상과 불순물 농도분포에 대한 연구 (A Study on the Lattic Damages and Impurity Depth Profiles of ${BF^+}_2$ Ion Implanted Silicon)

  • 권상직;백문철;차주연;권오준
    • 대한전자공학회논문지
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    • 제25권3호
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    • pp.294-301
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    • 1988

  • A study on the lattice damages and impurity depth profiles have been performed with BF2 ion implanted silicon materials. Electrical measurement, SIMS and TEM analysis techniques were used in order to identify the reverse annealing phenomena, impurity depth profiles and lattice damages. A typical reverse annealing phenomena were shown at the dose of 1x10**15/cm\ulcorner and non-reverse annealing at the dose of 5x10**15/cm\ulcorner This was explained with the formation of the amorphous region at BF2+ ion implantation with high dose. That is, the amorphous reigons were recrystallized centrated at certain regions were measured by SIMS technique. The dislocation loops-like crystalline defects were observed with TEM cross sections, which were formed at the lattice damaged region during annealing process.

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The relation between optical diffraction pattern and domain size in blue phase

  • Lee, Ho-Hyun;Kim, Jong-Hyun;Kikuchi, H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.942-944
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    • 2009

  • Blue phase shows several different reflection colors from the randomly oriented domains and crystal direction. Also there are variations in the size of domains. The domain size is dependent on the temperature gradient. With smaller cooling rate of temperature, the domain size was increased compared with rapid cooling. With injection of light of specific wavelength, we find that the diffraction patterns were occurred around the light spot in the cell of blue phase. It was supposed to be from the matching of the phase retardation and domain size. However, actually the diffraction pattern is reflecting the lattice structure in double twist of the blue phase. The lattice constant from the radius of diffraction patterns shows very similar one from the reflection spectrum, which indicates the internal lattice constant in double twist of the blues phase.

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