Tuning magnetic order in the van der Waals metal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Fe</mml:mi><mml:mn>5</mml:mn></mml:msub><mml:msub><mml:mi>GeTe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math> by cobalt substitution

The magnetic van der Waals materials with the highest ordering temperatures are generally metallic ferromagnets, such as Fe${}_{5}$GeTe${}_{2}$ with a Curie temperature near 300 K. In this work, the authors have demonstrated an ability to produce an antiferromagnetic state with an enhanced critical temperature by substituting cobalt for iron. While such a change to the magnetism is not uncommon, the important finding here is that the change in magnetic order is coupled not just to the chemical modification but also to a change in layer stacking that is induced by the cobalt substitution.