Synthetic beta-K(0.33)V2O5 nanorods: a metal-insulator transition in vanadium oxide bronze.

We found a linear relationship between the metal-insulator transition (MIT) temperature and the A(+) ionic radius of the beta-A(0.33)V(2)O(5) bronze family, leading our attention to beta-K(0.33)V(2)O(5) which has been neglected for a long time. We have introduced a facile hydrothermal method to obtain the single-crystalline beta-K(0.33)V(2)O(5) nanorods. As expected, both the temperature-dependence of the resistivity and magnetization demonstrated MITs at about 72 K for beta-K(0.33)V(2)O(5), thus matching well with the linear relationship described above. The beta-K(0.33)V(2)O(5) was assigned as a new member of the beta-A(0.33)V(2)O(5) bronze family for their similar crystal and electronic structures and their MIT property; this addition enriches the beta-A(0.33)V(2)O(5) bronze family.