Role of chemical pressure on the electronic and magnetic properties of the spin- 12 kagome mineral averievite

We investigate the electronic and magnetic properties of the kagome mineral averievite (CsCl)Cu5V2O10 and its phosphate analog (CsCl)Cu5P2O10 using first-principles calculations. The crystal structure of these compounds features Cu2+ kagome layers sandwiched between Cu2+-P5+/Cu2+-V5+ honeycomb planes, with pyrochlore slabs made of corner-sharing Cu tetrahedra being formed. The induced chemical pressure effect upon substitution of V by P causes significant changes in the structure and magnetic properties. Even though the in-plane antiferromagnetic (AFM) coupling J1 within the kagome layer is similar in the two materials, the interplane AFM coupling J2 between kagome and honeycomb layers is five times larger in the P variant, increasing the degree of magnetic frustration in the constituting Cu tetrahedra.