Title page for etd-0723112-165505


[Back to Results | New Search]

URN etd-0723112-165505
Author Ching-Yuan Chen
Author's Email Address No Public.
Statistics This thesis had been viewed 5585 times. Download 1221 times.
Department Physics
Year 2011
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Pressure and doping effects on the anomalous phase transition in ternary superconductor Bi2Rh3Se2
Date of Defense 2012-06-10
Page Count 73
Keyword
  • superconductivity
  • charge-density-wave
  • structural transition
  • Bi2Rh3Se2
  • pressure effect
  • doping effect
  • selected area electron diffraction
  • Abstract Bi2Rh3Se2 have been known as a charge-density-wave (CDW) superconductor, where the superconducting critical temperature Tc and the CDW phase transition are about 0.7 K and 250 K, respectively. Since there has no definite proof that the anomaly at around 250 K comes from charge-density-wave, we wished to provide another evidence to study whether the superconductor had the properties of CDW by electric resistivity measurements applied different pressures. Bi2Rh3Se2 was prepared by using the solid state reaction method and heating in the quartz tube. After the sample was synthesized, the quality was identified by XRD, MPMS, and specific heat probe. With the confirmation of the above-mentioned measurements, we can determine the sample’s quality is good. Furthermore, temperature-dependent resistivity (2-340 K) under pressure (up to 22.23 kbar) on the ternary superconductor Bi2Rh3Se2 are
    performed to study the possible coexistence of CDW and superconductivity. Interestingly, the resistive anomaly occurred at Ts~250 K, is shifted to higher temperature with increasing pressure. This experimental finding is not consistent with a traditional CDW transition. Moreover, the temperature-dependent Transmission Electron Microscopy (TEM) electron
    diffraction is evident a structural phase transition from space group “C1 2/m 1” (Ts > 250 K) to “P1 2/m 1” (Ts < 250 K). Finally, We do the Co doping to make sure the effects of chemical pressure on this phase transition. The results are opposite to imposed by physical pressure that the transition is shift to lower temperature with more Co inside the sample.
    Advisory Committee
  • H. Chou - chair
  • J. L. Her - co-chair
  • J.-Y. Lin - co-chair
  • H. D. Yang - advisor
  • Files
  • etd-0723112-165505.pdf
  • Indicate in-campus at 0 year and off-campus access at 1 year.
    Date of Submission 2012-07-23

    [Back to Results | New Search]


    Browse | Search All Available ETDs

    If you have more questions or technical problems, please contact eThesys