How Iron Doping Reshapes a Magnet's Pattern
A layered magnet is like a stack of paper: each sheet is a thin crystalline layer, and foreign atoms can be inserted between them like bookmarks. In the material Co₁₋ₓFeₓNb₃S₆, some cobalt atoms are replaced by iron, and this substitution acts like changing the paper type in the stack. The sheets start vibrating differently, and the whole stack responds differently to a magnetic field.