Further Chemico -physical Studies on the High Temperature Interactions of Ammonium Vanadate and I or Vanadium Oxide with Na -, KHS04 in the Solid State

Abstract

The interest of the present thesis is due to the important applications of

V-bronzes in solar cells, photocells and fuel cells industries.

In the present thesis, new solid solution vanadate bronzes [Na1.8oV205- NazVO(S04)2- NaV(S04)z]; [KuiVJOs- (VO)J(S04)s- KV(S04)z]; [KVOJ­ K(NH4)zVOJ]; [NaoJJVzO,-NaVJOs]; [Lio.JJVzOs-LiV60Js]; [KVJOs- K3Vs014]; [KV03-K3V5014]; [LiuzVJOs-NaVJOs-Nao.JJVzOs]; and [LiuzVJOs-KzVsOzJ] have been prepared by the reaction of alkali carbonate and alkali bisulphate with V205 and NH4V03 (alkali= Li, Na, K) in I :I molar ratio. The mixtures were ground mix, fired and sintered at(400-500-600)'c carefully for 24 hr.. On these bronzes, numerous measurements have been undertaken namely, X-ray diffraction (XRD), infrared absorption spectra (IR), UV/visible electronic absorption spectra, thermogravimetric analysis (TGA), differential thermal analysis (DTA), and the temperature dependence of electrical conductivity; and as a function of d'-absorbed dose. Results obtained were

interpreted and discussed in details together with evaluation of some

parameter including the material transport properties and activation energies for J" -induced carrier liberation. Accordingly, the present thesis results and

their deductions are in full conformity. And the promising new materials prepared and investigated led to new information, tQ be added to the literature agenda of magneto- electronic and nuclear vanadium bronzes. Therefore, the major goal of the present thesis is successfully established.