Towards electronic structure characterization of multiferroic alloys of 2D Transition-Metal dichalcogenides by means of ARPES

Transiton-metal dichalcogenides are a family of materials that has been of interest because of its 2D intrinsic character, their novel properties and, exotic ground states including charge density wave, superconductivity and topological insulators.

Alloys of TMDs are a platform to study the inherited properties of pattern compounds to its mixtures, and to look for the optimization of certain properties as doping changes. Recently was shown the emergence of multiferroic states in alloys of WTe2 and WSe2, namely W[Se1-xTex]2(1-δ) being x the tellurium fraction and δ the chalcogen vacancies [1]. In that work was proposed that chalcogen vacancies could play an important role as the physical mechanism behind ferromagnetism and ferroelectricity.

Photo-emission (PS) and Angle-resolved Photo-emission spectroscopy (ARPES) have been used to study pure composites WTe2 and WSe2 but to the best of our knowledge it does not exist any experimental report on the intermediate compositions W[Se1-xTex]2. It has been observed that the structure of the layered alloys W[Se1-xTex]2 is modified from 2H to 1Td from changing the tellurium doping fraction.

In this work we seminar we will show present some insights on the magnetic behavior of W[Se1-xTex]2(1-δ) for samples with almost perfect stoichiometry δ=0 and, some preliminary results of the electronic structure measurements performed by angle-resolved photo-emission spectroscopy (ARPES).

For the studied set of samples of 2H-W[Se1-xTex]2(1-δ), we will present measurement of band structure at ΓM, and ΓK, high symmetry planes, and energy maps at different binding energies for samples with for different tellurium doping fractions. For future work we expect to explore the electronic structure features for higher tellurium fractions x>0.6 in which the alloys are expected to be metallic.