Published online by Cambridge University Press: 01 February 2011
Sol-gel derived Nb2O5 thin films crystallize to a stable hexagonal phase on annealing at 600°C in air. These films have been intercalated with Mg2+ ions for the first time and the structural and the optical changes on intercalation have been reported. Films were intercalated and deintercalated with Mg2+ ions in galvanostatic mode. Mg intercalated films show about 35% transmittance variations in the entire spectral range. The FTIR studies show the formation of Mg-O-Nb bonds along with the formation of Nb-OH and Mg-O bonds. Small quantities of water is adsorbed during intercalation resulting in the formation of Mg(OH)2. The coloration is completely reversible on deintercalation. Formation of MgNb2O6 phase is seen on intercalation with 1M concentration of the electrolyte, which is found to be 'x' dependent, where ‘x’ is the ratio of the intercalated ions to the Nb atoms. 0.1 M electrolyte does not show the formation of this phase.