Formation of Sm 2+ lons in Sol‐Gel‐Derived Glasses of the System Na 2 O‐Al 2 O 3 ‐SiO 2

Samarium ions (Sm 2+ ) incorporated into aluminosilicate glasses by a sol‐gel process showed persistent spectral hole burning at room temperature. Gels of the system Na 2 O‐Al 2 O 3 SiO 2 synthesized by the hydrolysis of Si(OC 2 H 5 ) 4 , Al(OC 4 H 9 ) 3 , CH 3 COONa, and SmCl 3 ·6H 2 O were heated in air at 500°C, then reacted with H 2 gas to form Sm 2+ ions. Whereas Al 3+ ions effectively dispersed the Sm 3+ ions in the glass structure, Na + ions were not effective. The Al 2 O 3 ‐SiO 2 glasses proved appropriate for reacting the Sm 3+ ions with H 2 gas and exhibited the intense photoluminescence of Sm 2+ ions. The reaction of Sm 3+ ions with H 2 in the Al 2 O 2 ‐SiO 2 glasses was determined by first‐order kinetics, and the activation energy equaled 95 kJ/mol. At 800°C, the maximum photoluminescence of the Sm 2+ ions was achieved within 20 min.