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Research Outcome Produced by a Team Comprised of an Undergraduate Student from the Chemical Engineering and...

  • 작성처
  • Date2022.06.08
  • 12705

Research Outcome Produced by a Team Comprised of an Undergraduate Student from the Chemical Engineering and Materials Science Major and Graduate Students Published in an SCI-grade Journal


A phase transition in two-dimensional (2D) materials first identified using nano-radiation beams

Excellent results of joint research alongside graduate student mentors produced through a practical class for undergraduate students  


(from left) Lee Ha Heun, Yim Eunji, Kang Seohui


Senior student Yim Eunji from the Chemical Engineering and Materials Science major of the ELTEC College of Engineering and graduate students Lee Ha Heun and Kang Seohui (advisor: Prof. Suyeon Cho) from the System Health Convergence major, who were chosen for the fourth phase of the Brain Korea 21 (BK21) Project (Director: Prof. Oran Kwon), published the results of joint research on a phase transition in 2D materials using nano-radiation beams that was conducted with a team led by Dr. Chiang from the National Synchrotron Radiation Research Center (NSRRC) based in Taiwan. 


The outcome of this research, supported by the Overseas Large-scale Research Facility Utilization Support Project of the National Research Foundation, was published under the title of “Local phase transition at crack edges of Mo1-xWxTe2 polymorphs” in the online edition of Applied Surface Science (IF: 6.707, top 4.76 percent of JCR), an SCI-grade journal. 


A structural phase transition in 2D materials has attracted considerable attention in academia as it enables reversible conversion between semiconductors and conductors caused by the external environment. The research team from the Chemical Engineering and Materials Science major analyzed the nanoscale physical properties of a structural semiconductor-to-metal phase transition in a thin Mo1−xWxTe2 alloy sample with a thickness of several nanometers using nano X-ray diffraction and nano X-ray fluorescence with nano-radiation beams. As a result, the research team confirmed that, when a sample is synthesized in an alloyed form, the distribution of tungsten (W) becomes uneven at the critical point of a phase transition, and that the higher the tungsten content, the lower the amount of energy required for a phase transition. The research team identified the effects of substitutional elements in 2D materials on a structural phase transition therein. This is expected to further expand the applications of 2D materials used in a wide range of areas including energy conversion and optoelectronic devices.


In particular, this research was developed into a thesis led by Lim Eunji alongside graduate student mentors Lee Ha Heun and Kang Seohui in a seasonal class named “Advanced Chemical Engineering and Materials Science Lab” conducted by the Chemical Engineering and Materials Science major. The class is a practical course in which students conduct self-directed research under the guidance of a professor in the laboratory of the full-time faculty member during a school vacation, and is continuously resulting in outstanding achievements such as allowing students to carry out self-directed research, give a presentation at an international conference and present a senior thesis.