Fabrication, microstructure and electrical conductivity of V2O5 ceramics

V2O5 gels corresponding to the formula V2O5 . nH(2)O with n = 2.07, 0.5, and 0.2 have been prepared by the hydrolysis of VO(OC2H5)(3), followed by washing and drying. After dehydration, V2O5 crystallizes at 310 degrees to 400 degrees C. V2O5 powders with strip-like particles are produced after heating at 630 degrees C. Well-densified V2O5 ceramics (97.7% of theoretical) have been fabricated by the combined use of hot pressing (630 degrees C/2h/30MPa) and hot isostatic pressing (630 degrees C/1h/196MPa). The texture is of a plate structure, the grain being approximate to 30 mu m long and approximate to 6 mu m wide. Electrical conductivities have been measured in the temperature range of 25 degrees to 600 degrees C. Activation energies are determined to be 0.09 and 0.18 eV for initial and final stages, respectively.