Spectroscopic properties of Sm-containing yttrium-aluminoborate glasses and analogous huntite-like polycrystals

Crystallization and luminescence properties of (Sm x Y1 – x )2O3–Al2O3–B2O3 glass

“…According to XPA the powders obtained by solid-phase synthesis contained only the huntite-like YAl 3 (BO 3 ) 4 and SmAl 3 (BO 3 ) 4 crystals (see, for example, JCPDS card No. 18-0058) or their solid solutions (Fig.…”

“…29-0010), yttrium borate YBO 3 and samarium SmBO 3 (JCPDS Nos. 13-0479 and 16-0277, respectively) as well as the huntite-like phases YAl 3 (BO 3 ) 4 and SmAl 3 (BO 3 ) 4 (JCPDS Nos. 72-1978 and 18-0058, respectively) or their solid solutions.…”

Effects of ultraviolet excitation on the spectroscopic properties of Sm3+ and Tb3+ doped aluminophosphate glasses

“…Among the processes responsible for the decrease in intensity of the fluorescent level with temperature we must account for the multiphonon relaxation and energy transfer mechanisms via cross relaxation processes. Concerning the first process, it should be emphasized that a high energy gap ($7200 cm À1 [10][11][12][13]) occurs between the 4 G 5/2 fluorescent level and its lower lying energy level, preventing this process, namely in hosts with low phonon frequencies cutoff such the ones measured in this work. This means that a likely explanation for the observed luminescence quenching at higher temperatures is related to cross-relaxation mechanisms, identified in Fig.…”

“…This means that a likely explanation for the observed luminescence quenching at higher temperatures is related to cross-relaxation mechanisms, identified in Fig. 2c, among the excited levels of the Sm 3+ donors and the ground state of the nearby Sm 3+ acceptors [10][11][12][13]. Therefore, and since this process is mediated by vibronic coupling, it is expected that a removal of such non-resonant nonradiative processes should occur at lower temperatures, assuming 4.…”

“…This evidence of a non-exponential decay indicates that an energy-transfer process through cross relaxation should be considered to account for the non-radiative decay. This is a common behavior observed in samarium doped glasses [10][11][12][13] where the nature of the non-exponential decay curves has been analyzed in the framework of the InokutiHirayama (IH) model in absence of migration [14] and explained by the different natures of the ion-ion interactions such as dipole-dipole, dipole-quadrupole and quadrupole-quadrupole [14].…”