Effects of samarium (III) oxide content on structural investigations of the samarium–vanadate–tellurate glasses and glass ceramics

Abstract Glasses of the system xSm 2 O 3 ∙(100-x)[6TeO 2 ∙ 4V 2 O 5 ] where 0 ≤ x ≤ 50 mol% were prepared and investigated. IR and UV–VIS spectra show that with increase x, the network continuity breaks down with the formation of the larger numbers of non-bridging oxygen. The accommodation of the network with the excess of oxygen ions is possible by the depolymerization of the vanadate network in shorter chains, especially ortho- and pyrovanadate structural units. In order to improve the local orders and to develop crystalline phases the glass samples were kept at 275 ° C for 7 h. Some structural changes were observed and new crystalline phases, namely Te 2 V 2 O 9 and SmVO 4 crystalline phases appeared in the structure of the samples. Our UV–VIS spectroscopic data show the conversion of the Sm + 3 to Sm + 2 species in same time with the oxidation of V + 3 , + 4 to V + 5 ions.