Origin of the Anomalous Electrical Transport Behavior in Fe-Intercalated Weyl Semimetal Td-MoTe2

Weyl semimetal T-d-MoTe2 has recently attracted much attention due to its intriguing electronic properties and potential applications in spintronics. Here, Fe-intercalated T-d-FexMoTe2 single crystals (0 < x < 0.15 ) are grown successfully. The electrical and thermoelectric transport results consistently demonstrate that the phase transition temperature T-S is gradually suppressed with increasing x. Theoretical calculation suggests that the increased energy of the T-d phase, enhanced transition barrier, and more occupied bands in 1T ' phase is responsible for the suppression in T-S. In addition, a rho(alpha)-lnT behavior induced by Kondo effect is observed with x >= 0.08, due to the coupling between conduction carriers and the local magnetic moments of intercalated Fe atoms. For T-d-Fe0.15MoTe2, a spin-glass transition occurs at approximate to 10 K. The calculated band structure of T-d-Fe0.25MoTe2 shows that two flat bands exist near the Fermi level, which are mainly contributed by the d(yz) and dx2-y2${{\rm{d}}_{{x<^>2} - {y<^>2}}}$ orbitals of the Fe atoms. Finally, the electronic phase diagram of T-d-FexMoTe2 is established for the first time. This work provides a new route to control the structural instability and explore exotic electronic states for transition-metal dichalcogenides.

Automated summary

Fe-intercalated T-d-FexMoTe2 single crystals (0 < x < 0.15) were successfully grown and it was found that the phase transition temperature T-S is gradually suppressed with increasing x. Theoretical calculation suggests that the increased energy of the T-d phase, enhanced transition barrier, and more occupied bands in 1T' phase is responsible for the suppression in T-S. In addition, a rho(alpha)-lnT behavior induced by Kondo effect is observed with x >= 0.08, due to the coupling between conduction carriers and the local magnetic moments of intercalated Fe atoms. A spin-glass transition occurs at approximate to 10 K for T-d-Fe0.15MoTe2. The calculated band structure of T-d-Fe0.25MoTe2 shows that two flat bands exist near the Fermi level, which are mainly contributed by the d(yz) and dx2-y2 orbitals of the Fe atoms. The electronic phase diagram of T-d-FexMoTe2 is established for the first time in this work.