• Title/Summary/Keyword: novel materials

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A resistivity anomaly at 380 K in reproduced LK-99

  • Sangjin Kim;Kwang-Tak Kim;Jeonghun Kang;Dong-Hyeon Gim;Yoon Han Lee;Kee Hoon Kim
    • Progress in Superconductivity and Cryogenics
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    • v.25 no.4
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    • pp.10-13
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    • 2023
  • To confirm the room-temperature superconductivity at ambient pressure as claimed in recent arXiv preprints by Lee et al., we followed the original authors' systematic solid-state synthesis recipe to reproduce Cu-doped Pb-apatite, known as LK-99. Using X-ray diffraction and Raman spectroscopy, we identified inclusion of various impurities alongside the apatite phase in our sample. While the sample exhibited an overall semiconducting behavior in electrical transport, an intriguing resistivity anomaly at 380 K was observed, possibly originating from a structural phase transition of the Cu2-δS impurity. Based on the transport and magnetization measurements, we conclude that the sample is a non-magnetic semiconductor, with absence of superconductivity.

The Novel Liquid Crystal Materials for AM-LCDs

  • Yamaguchi, T.;Kibe, S.;Matsui, S.;Yamamoto, H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.924-929
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    • 2002
  • We have developed the novel liquid crystal materials with a difluoromethyleneoxy (CF2O) moiety as a linkage group in order to satisfy the diversified various requirements for AM-LCDs. These novel CF2O LC materials have excellent physical properties that are high dielectric anisotropy, low viscosity and wide nematic temperature ranges. Physical properties measurement results that mixtures containing CF2O LC materials have suitable for characteristics for AM-LCDs. The CF2O LC materials are excellent compound for quick response and low driving voltage application.

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