Toward strain control of magnetism in few-layer CrI3

Student: Salem Wright

Major Professor: Dr. Hugh Churchill 

Research Area(s):

Microelectronics

Nanoscience & Engineering

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Background/Relevance

 

  • The discovery of graphene ignited research into atomically thin materials, which can be manipulated to create new quantum devices dependent on the thickness of the materials
  • CrI3 is a known monolayer ferromagnet that can be cleaved into atomically thin layers for use in quantum devices
  • It is predicted that biaxial compressive strain of CrI3 will result in the formation of a quantum spin liquid, which is useful for quantum computing

Innovation

 

  • Biaxial strain of few-layer CrI3 will be used to tune its Curie temperature

Approach

  • Create a polypropylene substrate with a speckle pattern using electron beam lithography
  • Exfoliate thin flakes of CrI3 onto a silicon substrate
  • Use optical contrast techniques to measure the thickness of exfoliated layers
  • Transfer few-layer CrI3 onto a polypropylene substrate to apply compressive biaxial strain
  • Future work will use an optical cryostat to measure the Kerr rotation of few-layer CrI3 to determine the Curie temperature

    Key Results

    • The thickness of few-layer CrI3 flakes was measured using optical contrast
    • Biaxial strain of polypropylene substrates was measured using digital image correlation

    Conclusions

     

        • The thickness of few-layer CrI3 can be measured using optical contrast
        • The biaxial strain of polypropylene can be quantified using digital image correlation
        • CrI3 flakes can be transferred from a silicon substrate onto a polypropylene substrate for compressive biaxial strain