Raman Signature of Layer Number and Crystal Quality of Chromium Triiodide

Gaihua Ye; Eric Davis; Eric Davis; Eric Davis; Eric Davis; Eric Davis; Eric Davis; Eric Davis; Eric Davis; Eric Davis; Eric Davis

Raman Signature of Layer Number and Crystal Quality of Chromium Triiodide

ORAL

Abstract

Chromium triiodide (CrI$_{\mathrm{3}})$ has recently been shown to host Ising ferromagnetism down to the monolayer limit, which stimulates numerous ideas of device applications based on this two-dimensional (2D) ferromagnet. We performed polarized Raman spectroscopy studies on phonon modes as a function of CrI$_{\mathrm{3}}$ thickness and ambient exposure time. In pristine samples, Raman selection rules for intralayer phonons remain the same not only above and below the structural phase transition, but also in bulk and atomic layers. This indicates that the interlayer coupling plays a negligible role on the symmetry properties of intralayer phonons. Despite the consistency of selection rules between pristine bulk and thin layer CrI$_{\mathrm{3}}$, the ratio between the A$_{\mathrm{g}}$(C$_{\mathrm{3i}})$ and E$_{\mathrm{g}}$(C$_{\mathrm{3i}})$ modes, at \textasciitilde 128 and \textasciitilde 107 cm$^{\mathrm{-1}}$ respectively, is a good indicator for labeling the layer numbers at room temperature, while the frequency separations between the magnetic excitation modes and its neighboring A$_{\mathrm{g}}$ phonon modes serve as another thickness marker below magnetic phase transition temperature $T_{\mathrm{C}}$. Raman spectra from CrI$_{\mathrm{3}}$ crystals after moderate ambient exposure are indistinguishable from that of the pristine CrI$_{\mathrm{3}}$ at room temperature, but exhibit significant differences below $T_{\mathrm{C}}$

Oct. 25, 2019, 5:36 PM – Oct. 25, 2019, 5:48 PM

Authors

Gaihua Ye

Texas Tech University
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory
Eric Davis

University of Texas at Arlington, Sultan Qaboos University, UTA HEP group, Department of Integrated Bio \& Nano Systems, University of Houston, Houston, TX 77204, USA, Department of Electrical and Computer Engineering, Nano Tech Center, Texas Tech University, University of Michigan, University of Waerloo, Canada, Texas Tech University, Dept of Mechanical Eng, TTU; Dept. of Physics and Astronomy, TTU, Dept of Cell Biology and Biochemistry, TTU Health Sci Ctr, Dept of Physics and Astronomy, TTU, Dept of Mechanical Engineering, TTU, Dept of Physics and Astronomy, TTU; Sch of Health and Sci, Purdue Univ, Dept of Mathematical and Systems Engineering, Shizuoka Univ, Department of Physics, University of Texas at Dallas, Richardson, TX 75080, Department of Physics, University of Texas at Dallas, Richardson, TX 75080., LeTourneau University, None, University of Waterloo, Canada, Texas Tech Univ, Trinity University, the University of Texas at Dallas, Texas Tech University, Lubbock, TX, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada, University of Dallas, Liverpool John Moores University, University Of Houston, Biolog Department, TCU, Home Schooled high school student, Los Alamos National Laboratory