Single crystal growth and characterization of lanthanum–neodymium oxalate octahydrate

Single crystals of mixed lanthanum–neodymium oxalates are grown by gel diffusion method using agar gel as a medium of growth. The crystals grow in the agar gel with hexagonal morphology having (001), (110) and (010) as habit faces. Single crystal X-ray diffraction results show that the crystals belong to monoclinic system with cell parameters; a=10.344(2) Å, b=9.643(6) Å, c=11.721(2) Å, β=118.7 (2)° , bearing the space group P2/c. Fourier transform infrared spectrum of the crystals indicates the presence of water and other functional groups associated with the oxalate ions. Thermogravimetric and differential thermal analysis support the presence of 8H2O molecules attached to the lanthanum–neodymium crystal lattice. The thermal decomposition in the nitrogen atmosphere leads to the formation of mixed lanthanum–neodymium oxide as the final product. Energy dispersive analysis of X-rays along with elemental analysis suggests the stoichiometry of the gel grown crystals to be La1.5Nd 0.5(C2O4)3·8H2O.

► In this paper growth of single crystals of mixed rare earth oxalates in agar gel is reported.
► The single crystals of lanthanum neodymium oxalate octahydrate have chemical formula as La1.5Nd0.5(C2O4)3·8H2O.
► The crystals have hexagonal morphology with well defined habit faces and belong to monoclinic system with non-centrosymmetric space group P2/c.
► The cleavage planes of the grown crystals are parallel to (010) plane.
► Thermogravimetric analysis shows the association of eight water molecules with the crystal lattice of LNO.