Solid solution Ca 12 Al 14 O 33±δ : V 5+ , Mo 5+

A solid solution of the composition Ca 12–x (Al 14 V x )O 33+ δ (0 ≤ х ≤ 0,07) was synthesized. A combination of methods established the charge state of vanadium in a solid solution. The principle of filling with a dopant crystallographic positions in the structure of mayenite is proposed: vanadium cations replace a small number of aluminum positions, presumably in octahedral coordination. The temperature dependence of the electrical conductivity of Ca 11,93 (Al 14 V 0,07 )O 33+ δ  was studied by the impedance spectroscopy. It is shown that doping of mayenite with vanadium increases the value of electrical conductivity by an order of magnitude.