Local structural study of MoTe₂ using atomic pair distribution function and EXAFS techniques

Below 250K, average scattering techniques have shown that 1T’ MoTe₂ undergoes a first order structural phase transition (SPT) to a non-centrosymmetric orthorhombic, T_d phase with emergence of Weyl points protected by broken inversion symmetry. However, due to the similarity of structures of these distinct phases and a small energy barrier between them, various distortions are observed at macroscopic as well as atomic scales. We present the local structure study of 1T’ MoTe₂ over various temperatures ranging from 95K to room temperature by using scattering techniques more suited to the study local structures. We observed that on lowering the temperature interlayer atomic distances change significantly however the intralayer distances do not. This has been investigated using both small box and large box modelling approaches. From large box modelling analysis, we show effects of stacking faults and rotation of layers on the interlayer atomic distances which are consistent with the experimental observation.Understanding the interlayer behavior on MoTe₂ through local structure studies can help to clarify some of the outstanding questions on the SPT and its effects on the emergence of the Weyl points at low temperatures.