Tb2Co(B2O5)2 and Tb2Cu(B2O5)2 - two new borates with gadolinite-type structures

Using high-pressure/high-temperature synthesis methods, it was possible to increase the number of known borates with a crystal structure derived from gadolinite. Syntheses of Tb2Co(B2O5)(2) (8 GPa, 1000 degrees C) and Tb2Cu(B2O5)(2) (11 GPa, 650 degrees C) were carried out in a Walker-type multianvil device. The crystal structures were determined by singlecrystal X-ray diffraction methods and Rietveld refinements of the powder patterns. The new compounds were further characterized by their infrared spectra. The lanthanoid cobalt and copper borates Tb2Co(B2O5)(2) and Tb2Cu(B2O5)(2) crystallize in the monoclinic space group P2(1)/c (no. 14) with the unit cell parameters a = 4.5630(1), b = 7.2991(2), c = 9.4161(2) angstrom, and beta = 91.14(1)degrees for the cobalt and a = 4.5757(1), b = 7.3078(2), c = 9.3771(3) angstrom, beta = 90.73(1)degrees for the copper compound.

Automated summary

Using high-pressure/high-temperature synthesis methods, new borates Tb2Co(B2O5)(2) and Tb2Cu(B2O5)(2) with crystal structures derived from gadolinite were successfully synthesized. The crystal structures were determined by single-crystal X-ray diffraction methods and Rietveld refinements of the powder patterns. The lanthanoid cobalt and copper borates crystallize in the monoclinic space group P2(1)/c with specific unit cell parameters.