Preparation, crystal structure and photoluminescence of Mn ²-doped magnesium pyroborates solid solutions, (Mg _1xMn_x)₂B₂O₅

Solid solutions of manganese(II)-doped magnesium pyroborate, ((Mg _1-xMn_x)₂B₂O₅, 0<x≤0.30, triclinic system, space group: P1̄ (no. 2)), were synthesized by solid state reaction. The unit cell parameters were refined by the Rietveld method of powder X-ray diffraction patterns. (Mg _1-xMn_x)₂B₂O₅ showed broad red emission at 670 nm under 414 nm excitation. The wavelengths of the emission peak did not depend on the manganese content. Absorption of the dd transitions of Mn² ions was observed in the photoluminescence excitation spectra. The emission intensity reached the maximum at a Mn content (x) of 0.05 and decreased with increasing x from 0.05 to 0.30.