Early-onset of pressure-induced metallization in iron-doped multilayered molybdenum disulfide

Abstract

Chemical doping-induced magnetism in semiconducting transition metal dichalcogenides (TMDC) can have significant implications in electrically controlled spintronics. In addition, strain engineering of the layered structures of TMDCs can further allow for tuning the interlayer van der Waals (vdW) bonds and controlling their electronic properties. Of particular interest are the effects of Fe doping coupled with strain tuning on the vdW bonds and associated electronic properties of Fe:MoS2. Here, we have investigated compressive strain tuning effects on the structural and vibrational properties of Fe:MoS2 using in situ angle-dispersive x-ray diffraction and Raman scattering spectroscopy at quasi-hydrostatic pressures up to 25.0(1) GPa. Our results indicate that Fe:MoS2 undergoes isostructural electronic transitions similar to those in pristine MoS2, but at significantly lower pressures. Sudden changes in the microscopic strain, Raman peak splitting, and phonon softening are observed at the transition pressures, suggesting that the structural instability introduced by the Fe dopants is responsible for the early onset of the transitions. The significant effects of Fe dopants on the interlayer vdW bonding, as well as the structural and phononic properties under compressive strain indicate a strategy for modulating the electronic and ferromagnetic properties of TMDCs.