High Entropy and Low Symmetry: Triclinic High-Entropy Molybdates
David Stenzel, I. Issac, Kai Wang, Raheleh Azmi, Ruby Singh, Jaehoon Jeong, Saleem Najib, Subramshu S. Bhattacharya, Horst Hahn, Torsten Brezesinski, Simon Schweidler, Ben Breitung
Abstract
Metal molybdates constitute a promising class of materials with a wide application range. Here, we report, to our knowledge for the first time, on the preparation and characterization of medium-entropy and high-entropy metal molybdates, synthesized by an oxalate-based coprecipitation approach. The high-entropy molybdate crystallizes in a triclinic structure, thus rendering it as high-entropy material with the lowest symmetry reported so far. This is noteworthy because high-entropy materials usually tend to crystallize into highly symmetrical structures. It is expected that application of the high-entropy concept to metal molybdates alters the material's characteristics and adds the features of high-entropy systems, that is, tailorable composition and properties. The phase purity and solid solution nature of the molybdates were confirmed by XRD, Raman spectroscopy, TEM, XPS, and ICP-OES.