Ferromagnetic interaction between A-site Cu spins in A-site-ordered perovskites A′Cu3Sn4O12 with A′ = Ca2+, Sr2+, Pb2+, and La3+

► The ground states of A′Cu3Sn4O12 with A′ = Ca2+, Sr2+ and Pb2+ are all FM insulator and the magnetic properties are determined primarily by the direct FM interaction between Cu2+ ions at the A-site. ► We replaced bivalent A′ ion by trivalent La ion and FM half-metallic property of LaCu3Sn4O12 is predicted. The interesting point in this substitution is that electron is injected into A-site Cu ions and the electronic configuration in this compound seems to be La3+Cu31.67+Sn44+O122-.