cm7b00871_si_001.pdf (1.53 MB)
Crystal Structure and Nontypical Deep-Red Luminescence of Ca3Mg[Li2Si2N6]:Eu2+
journal contribution
posted on 2017-04-03, 00:00 authored by Christine Poesl, Wolfgang SchnickRare-earth-doped
nitridosilicates exhibit outstanding luminescence
properties and have been intensively studied for solid-state lighting.
Here, we describe the new nitridolithosilicate Ca3Mg[Li2Si2N6]:Eu2+ with extraordinary
luminescence characteristics. The compound was synthesized by the
solid-state metathesis reaction in sealed Ta ampules. The crystal
structure was solved and refined on the basis of single-crystal X-ray
diffraction data. Ca3Mg[Li2Si2N6]:Eu2+ crystallizes in the monoclinic space group C2/m (no. 12) [Z = 4, a = 5.966(1), b = 9.806(2), c = 11.721(2) Å, β = 99.67(3)°, V = 675.9(2) Å3] and exhibits a layered anionic network
made up of edge- and corner-sharing LiN4 tetrahedra and
[Si2N6]10– bow-tie units.
The network charge is compensated by Ca2+ and Mg2+ ions. Upon irradiation with UV to blue light, red emission at exceptionally
long wavelengths (λem = 734 nm, fwhm ≈2293
cm–1) is observed. According to emission in the
near-infrared, application in LEDs for horticultural lighting appears
promising.