Figure 28.

(a) Schematics illustrating the combination of two structural motifs, i.e., that of transition-metal dichalcogenides TMC₂ (TM, transition metal; C, chalcogen) together with that of body-centered cubic iron to form Fe-rich vdW coupled ferromagnets of composition Fe_xGeC₂. (b) Three stable structures within the Fe_nGeTe₂ series with the values n = 3, 4, and 5 which were previously identified through ab initio calculations. Fe–Fe dumbbells are the common structural units that form multiple-layer Fe-rich slabs stacked through vdW-like coupling. As n increases, the number of nearest Fe neighbors per Fe atom gradually increases, which is expected to enhance the pair exchange interaction and, thus, T_c. All panels are adapted with permission under a Creative Commons CC BY-NC 4.0 license from ref (88). Copyright 2020 AAAS.