TY - JOUR
T1 - Local structure memory effects in the polar and nonpolar phases of MoTe2
AU - Petkov, Valeri
AU - Ren, Yang
N1 - Funding Information:
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award No. DE-SC0006877 and used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Thanks are due to K. Chapagain for the help with Rietveld analysis of XRD data.
Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/3/1
Y1 - 2021/3/1
N2 - We use total scattering to study the reversible transition between the polar 1T′ and nonpolar Td phases of layered MoTe2 taking place at 240 K. Whereas, macroscopically, the transition appears to be first order, locally, it is not. In particular, a great deal of the stacking sequence of Te-Mo-Te layers characteristic of the polar 1T′ phase persists locally in the nonpolar Td phase, and vice versa, over a broad temperature range extending about 100 K both below and above the transition. The intermixing ratio for the two sequences evolves gradually across the transition temperature, consistent with a second-order transition behavior. The presence of coexisting local polar and nonpolar regions and the resulting variety of internal interfaces where the spatial inversion symmetry is broken may be behind some of the unusual electronic properties of Td-MoTe2, including its putative type-II Weyl semimetal state.
AB - We use total scattering to study the reversible transition between the polar 1T′ and nonpolar Td phases of layered MoTe2 taking place at 240 K. Whereas, macroscopically, the transition appears to be first order, locally, it is not. In particular, a great deal of the stacking sequence of Te-Mo-Te layers characteristic of the polar 1T′ phase persists locally in the nonpolar Td phase, and vice versa, over a broad temperature range extending about 100 K both below and above the transition. The intermixing ratio for the two sequences evolves gradually across the transition temperature, consistent with a second-order transition behavior. The presence of coexisting local polar and nonpolar regions and the resulting variety of internal interfaces where the spatial inversion symmetry is broken may be behind some of the unusual electronic properties of Td-MoTe2, including its putative type-II Weyl semimetal state.
UR - http://www.scopus.com/inward/record.url?scp=85102878432&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.103.094101
DO - 10.1103/PhysRevB.103.094101
M3 - Article
AN - SCOPUS:85102878432
VL - 103
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 9
M1 - 094101
ER -