Soft-chemical reactions of the reduced niobium oxide: Rb1.51Nb10O17

Ion-exchange and deintercalation of Rb+ ions in Rb1.51Nb10O17 were found to occur only above 100 °C. The basic crystal structure is maintained during these soft-chemical reactions. Ion-exchange is accompanied with the incorporation of protons yielding (Rb,A,H)1.51Nb10O17 · nH2O (A = Li, Na, K, Cs). The maximum replacement was observed when ion-exchanging with K+ ions, giving the chemical composition K1.02Rb0.02H0.47Nb10O17 · 0.9H2O. The Rb+ ions were deintercalated up to Rb0.15Nb10O17. No evidence of superconductivity in the soft-chemical products was observed down to 4.2 K.