Insertion of MoO₃in Borophosphate Glasses Investigated by Magnetic Resonance Spectroscopies

Insertion of MoO 3 oxide in the mixed borophosphate glass network has been analyzed for the first time by advanced magnetic resonance spectroscopies. For the first time, the x MoO 3 -(100- x )(50PbO-10B 2 O 3 -40P 2 O 5 ) composition line has been investigated by 1D ( 11 B, 31 P, 95 Mo) and 2D-correlation NMR ( 11 B DQ-SQ, 11 B( 31 P) D-HMQC) at high magnetic field (18.8 T). The set of data allowed for analyzing both local and medium range orders and identifying the modifications in the BOB and/or BOP mixing induced by the MoO 3 insertion. In a second step, continuous wave EPR has been used to detect the presence of Mo 5+ ions, resulting from partial reduction of Mo 6+ during the melting stage, and the chemical environment around the Mo 5+ species has been documented for the first time by pulsed EPR technique (HYSCORE). Altogether, the data contribute to a better understanding of the glass network modifications induced by the MoO 3 insertion, including the nonlinear evolution of the glass transition temperature that has been explained by a modification of the glass network nature.