Flux Synthesis and Structural and Spectroscopic Characterization of a Cobalt Europium Trisilicate

Abstract

A trisilicate with a new structure type, CoEu 2 Si 3 O 10 , was obtained from molybdate-carbonate mixtures in Pt crucibles by using a high-temperature flux-growth method. The structural characterization of CoEu 2 Si 3 O 10 was done by evaluation of single-crystal X-ray diffraction data collected at three different temperatures (105, 293, and 370 K). The light violet crystals are monoclinic, space group P2 1 /n with a = [a] 3405 6.5620(13), b = 6.7207(13), c = 16.986(3) Å, β = 90.06(3)°, V = 749.1(3) Å 3 , and R(F) = 2.49 %, at room temperature. The new crystal structure type features layers parallel to (001) containing Si 3 O 10 groups and Co 2 O 10 dimers. The Si-Si-Si angle of the Si 3 O 10 unit is 115.7°. Raman spectroscopy and a study of the photoluminescence properties of the Eu 3+ ions in CoEu 2 -Si 3 O 10 were undertaken.