Synthesis of New Amorphous Metallic Spin Glasses M2SnTe4 (MCr, Mn, Fe, Co): Solvent Induced Metal‐Insulator Transformations

Precipitation of amorphous metallic spin glasses from solution is a novel, potentially general method. By this means, main‐group metal polyanions are oxidized by transition‐metal cations. The example which has been studied in most detail is Fe2SnTe4. This forms immediately as a black precipitate when methanolic solutions of anhydrous FeBr2 and K4SnTe4 are mixed at −20°C. The resistivity of pressed powder samples is low. In the presence of strong donor ligands, the FeTe bonds are selectively cleaved. Solid [Fe(en)2]2SnTe4 (orange) is an insulator.