Optical and magneto-optical spectra of europium-doped strontium tetraborate single crystals

Optical absorption, luminescence, magnetic circular dichroism and Faraday rotation spectra of Sr_0.95Eu_0.05B₄O₇ single crystals are studied. The crystal field parameter for europium ions is found to be equal to 790 cm⁻¹. Excitation spectrum of luminescence strongly differs from that of low-doped polycrystalline strontium tetraborate. The Verdet constant in the ultraviolet is comparable to that of terbium gallium garnet in the visible.