Pair luminescence in Cr3+ -doped Ba2Mg(BO3)2

Abstract Cr 3+ ions were introduced to the Ba 2 Mg(BO 3 ) 2 host to provide information about the site occupation, crystal field strength, and the site symmetry. The samples were synthesized by solid-state reaction. Emission observed under 440 nm excitation was characteristic for Cr 3+ ions in strong octahedral ligand field with Dq/B parameter ratio 2.74 and sharp R line at 698 nm. The charge mismatch between Cr 3+ dopant and Mg 2+ host ion is compensated by the creation of Cr 3+ pair in the vicinity of Ba or Mg vacancy. The emission decay curve is bi-exponential with decay times 1.2 and 13.3 ms.