Synthesis, crystal structure, characterization and luminescent properties of KBaTbB2O6

• Novel rare-earth borate KBaTbB2O6 was synthesized using a conventional solid-state reaction method.
• The crystal structure of KBaTbB2O6 has been determined by the Rietveld analysis.
• Tunable emission in red wavelength range was realized by controlling Eu3+ ions content.

Novel rare-earth borate KBaTbB2O6 was synthesized using a conventional solid-state reaction method. The crystal structure of KBaTbB2O6 has been determined by the Rietveld analysis, which demonstrates that the final chemical composition is K0.46Ba0.54Tb0.49BO3 and KBaTbB2O6 is isomorphous with KBaY(BO3)2 and crystallizes in the planar trigonal [BO3]3− group R-3 m with lattice parameters of a=5.4562(4) Å, c=17.8629(2) Å, and Z=3. Tunable emission in red wavelength range was realized by doping and controlling Eu3+ ions content into KBaTbB2O6. The critical energy transfer distance calculated by the concentration quenching theory was 6.64 Å and the energy transfer from Tb3+ to Eu3+ took place via a resonance-type mechanism.