The light induced valence change of europium in Sr2SiO4 ∶ Eu involving transient crystal structure†
Abstract
Sr2SiO4
∶ Eu3+ shows orange-red emission of Eu3+ substitutively present in two different Sr sites. The light-induced spectral changes from orange-red sharp line emission to yellow-white broad band are observed in Sr2SiO4
∶ Eu at room temperature under irradiation with short UV or X-rays. The spectral changes are attributed to the optically assisted