Role of vacancies and defects in the elastic, electric and magnetic properties of a 2D transition-metal dichalcogenide alloy

Multiferroic materials, which exhibit simultaneous ferromagnetic, ferroelectric, and/or ferroelastic orders, have attracted significant attention owing to their potential for energy-efficient data storage, ultrafast data processing, and clean energy conversion. The recent discovery of multiferroicity in bulk transition-metal dichalcogenides (TMDs), a widely studied family of 2D van der Waals materials, has generated interest in exploring multiferroics in 2D materials because of the possibility for developing nanoscale devices [1]. Understanding the fundamental physical properties and behavior of these compounds is crucial for elucidating their types of applications. While previous studies have focused primarily on magnetic and electric properties, our investigation extends to include elastic properties, offering a more complete picture of the behavior of these materials. Here, we present measurements of the structural, magnetic, piezoelectric, and elastic properties of different solid solutions of transition-metal dichalcogenides, such as W(TexSe1-x)2_{(1-δ )}, and study their evolution as a function of doping (x) and chalcogen vacancy/defect concentrations (δ), for different temperature regimes. These techniques provide initial insights into the effects of sample composition and vacancies on multiple ferroic orders and their coupling.

[1] G. Cardenas-Chirivi et al. npj 2D Mat. and Appl. 7 (2023) 54.