Crystal chemistry of (RE,A)_2M_3O_7 compounds (RE=y, lanthanide A=Ba, Sr, Ca; M=Al, Ga)

摘要

for their nonlinear optical properties and have potential as solid state lasers. Their structures have been refined using X-ray and neutron diffraction data and are related to gehlenite, Ca_2Al_2SiO_7, with M cations occupying al and Si sites and RE an A cations sharing the Ca site with no evidence for Ordering, although they occur in the ratio 1:1 because of stoichiometry; the M cations are Tetrahedrally coordinated.