Access to lanthanoid telluride nanoparticles: Liquid exfoliation of LnTe3 (Ln = La, Ho)

Highlights: • Ultrasonic treatment in several solvents gives very stable dispersions of LnTe₃. • Liquid exfoliation results in formation of 1–2 layer LnTe₃ nanoparticles. • Films prepared from the dispersions were high-oriented samples of LnTe₃. - Abstract: Although many of the nanoparticles containing lanthanoids are deeply investigated, the reports concerning chalcogenide materials are scarce. Comprehensive exploration of properties of these materials requires a proper preparation method avoiding hydrolysis and contamination with oxygen-containing products. Hence, in this case, the top-down approach could be preferable. In this study we demonstrated preparation of LnTe₃ (Ln = La, Ho) nanoparticles by liquid exfoliation method. Bulk tritellurides LaTe₃ and HoTe₃ afford stable dispersions in a number of common organic solvents under ultrasonic treatment. The size and morphology of nanoparticles in colloid solutions as well as films prepared from them were investigated by a number of methods (AFM, TEM, DLS, XRD, Raman). LnTe₃ form stable dispersions in alcoholic media with concentration up to 165 mg/L. In these dispersions nanoparticles exist as 1–2 layered charged flakes with lateral size 50–80 nm. The nanoparticles can be reassembled as films, which demonstrated orientation along 0 k 0 direction.