research papers
X-ray diffuse scattering from V0.90Nb0.10O2 shows that the metal-to-insulator phase transition which occurs around - 25°C without an overall structural change can be explained by local pairing of the vanadium atoms. This local order, which recalls the low-temperature insulating structure of pure VO2, is two dimensional and occurs in the (110) planes of the average rutile structure with little correlation between successive parallel (110) atomic planes.