LAUSR

Abstract This article reports on synthesis and spectroscopic characterizations of surface crystallized BaB4O7 nanocrystals doped with Sm and Sm:Yb rooted in borate glass which forms microsized ‘Spherulites’ while annealing for more than 06 h. Detailed nano and microstructural analysis were done using transmission, scanning electron microscopic and Polaroid optical microscope images; and XRD techniques which revealed the formation of cone - shaped BaB4O7 spherulites. Images under polarized light revealed birefringence property in tiny crystals rooted in glass- ceramic. A bright red dominated orange-red emission was observed under UV (266 nm) laser excitations. Emission intensity was found to be 08 multiple, in ceramics, then the glass counterpart. Formation of tiny crystals reinforces sharp emission peaks (FWHM ~ 1.6 nm) due to Sm3+ ions. We have confirmed formation of Yb2+, Yb3+ and Sm3+ ionic species in the lattice which leads infrared cascade downconversion emissions spanning in the wide range of 380–1000 nm through involvement of intervalence charge transfer from Yb2+ to Yb3+ ions.