March_2022_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | M A R C H 2 0 2 2 9 accumulated in HoMS, which operates as a heat reservoir to regulate the ther- mal flow. The work provides a new ave- nue for designing smart reactors for the green chemical industry, thus creating more opportunities for heat-related ap- plications and increasing the potential for efficient energy use. english.zzu.edu. cn, english.ipe.cas.cn/. HONEYCOMB CRYSTAL DISCOVERY Researchers from Tohoku Univer- sity and Osaka Prefecture University, both in Japan, reported a rare structur- al change in a mineral-like crystal that could lead to the development of new functional materials if controlled. Un- til now, scientists had only observed a few examples of cation dimerization in 3D transition metals with honeycomb The crystal structure of ilmenite-type magnesium vanadate (MgVO 3 ) with yellow lines defining the honeycomb lattice and thick lines indicating the location of V-V dimers. Courtesy of Hajime Yamamoto. lattice systems. 3D transition metals have specific properties and electrons that move about in the 3D orbital sur- rounding the atom. The research team used high pres- sure to synthesize the simple oxide ilmenite-type magnesium vanadium trioxide, mimicking the conditions of mineral formation deep in the Earth’s core. The team then used synchro- tron x-ray experiments to analyze the crystal’s structure and found that its honeycomb lattice developed vanadi- um-vanadium (V-V) dimers arranged in a ladder-like pattern at temperatures below 500 kelvin (227°C). Notably, the team also observed a magnetic to non-magnetic transition in the crystal’s properties when the temperature fell below 600 K. Next, the teamplans to explore the control of the V-V dimer state with mag- netic fields and pressure. “We might be able to use this to create new magnetic or electrical functions in this and simi- lar materials,” propose the researchers. www.tohoku.ac.jp/en.