Insulator-to-metal transition in vanadium sesquioxide: does the Mott criterion work in this case?

It is shown that the Mott criterion expressed by the simple relation a B(n c)1/3 ≈ 0.25 turns out to be quite successful in describing metal–insulator phase transitions not only in heavily doped semiconductors, but also in transition metal oxides such as VO2 and V2O3. It is found in this article that, in the case of a high-temperature transition ‘paramagnetic insulator – paramagnetic metal’ in vanadium sesquioxide, a B(n c)1/3 = 0.254. Difficulties connected with the analogous description of a low-temperature transition (‘paramagnetic metal – antiferromagnetic insulator’) in V2O3 are discussed.