Polymorphism of the Co–Te nanophases in mechanochemical synthesis

Abstract

The mechanochemical synthesis of all cobalt tellurides' phases is demonstrated in this work.

Mechanochemical Synthesis of Sustainable Ternary and Quaternary Nanostructured Cu2SnS3, Cu2ZnSnS4, and Cu2ZnSnSe4 Chalcogenides for Thermoelectric Applications

“…Mechanochemical syntheses via high-energy reactive milling offer the unique advantage of producing various disordered polymorphs of these compounds. This single-step and solvent-free method can alloy materials with different melting points, such as transition metals and chalcogenides, due to the highly entropic environment of the milling [ 15 , 16 , 17 , 18 ]. Such an environment also favors the disordering of these Cu-alloys.…”

Emerging 2D Cobalt Telluride (CoxTey): from Theory to Applications

“…Tiny variation in compound, structure and phase remarkably modifies and even changes the band structure, electronic and magnetic properties. [24,103] Although the main landmarks over the past researches are systematized in this review, to our best knowledge, the controlled synthesis and corresponding compoundstructure-property relationship is still lacking. Experimentally, more attempts upon synthesizing different cobalt tellurides with demanded stoichiometric ratio, lattice structure and crystal phase are worthy further studies.…”

“…approached ≈0.2 V, a big step closer in the industrialization of magnetic applications. [22,32,76] CoTe 2 , due to strain-modified bandgap and out-of-plane inversion symmetry, becomes function as active generator to harvest waste heat and mechanical deformation energy at varied temperatures. Profit from the hexagonal unit cell that six Te atoms surround each Co atom, layered CoTe 2 possesses excellent transparency, flexibility, and high surface-to-volume ratios, offering an ideal material candidate for thin and flexible devices.…”

“…Under scanning electron microscope and elemental energy dispersive spectroscopy, the films were consisted by many nanostructured domains with lateral dimension no more than 100 nm and the relative atomic ratio of Co: Te were determined to be 46: 54 and 32: 67, respectively. [ 74 ] Parallel to this, mechanochemical synthesis, [ 22 ] tellurization [ 75 ] and polyol reduction of ultrathin Te nanostructures [ 17 ] were excavated to selectively fabricate 2D Co x Te y with desired lattice structures and phases. More efforts in controlling the phase purity, crystallinity and the lateral dimension, may significantly boost the scientific advance of cobalt telluride and subsequent applications.…”

“…[10,11,12,13] Among various fantastic candidates, cobalt telluride (Co x Te y ) widely reputed as star catalysts for hydrogen/oxygen evolution reactions, [14,15] water splitting, [16] photo-/electro-catalytic chemistry, [17,18,19] and even energy storage devices, [20,21] was re-recognized with tunable ferromagnetism and paramagnetism and is potential for memory and spintronic devices. [22,23,24,25] Differentiating from traditional vdW magnets, the stoichiometric ratio of Co and Te varies from (1+𝛿):1 to 1:2 and the variation of crystal structure effectively modulates the band structure of Co x Te y from type-II Dirac semimetallic (1T-CoTe 2 ) to semiconducting (bandgap ≈2.5 eV, CoTe). [26,27,28] This extra degree of freedom enables Co x Te y taking centerstage for exploring spin fluctuation and other new physical paradigms.…”