CHARACTERIZATION OF GEL-GROWN NEODYMIUM HEPTAMOLYBDATE CRYSTALS

Neodymium hepta molybdate crystals grown from silica gels [1] are char acterized employing energy dispersine X-ray analysis, X-ray and electr on diffraction, infra-red spectroscopy, optical microscopy and scannin g electron microscopy techniques and the results obtained are presente d. The crystals are established to have the composition Nd(2)Mo(7)O(24 )27H(2)O. The results of electron diffraction studies indicate the mat erial to be thermally unstable. The crystals growing within the gel me dium exhibit varied morphologies including square and octagonal platel ets, cuboids, multifaceted crystals, coalesced and aggregated forms an d spherulites. The spherulitic morphology is shown to arise due to cry stallites adhering in a spherical envelope and are not as a result of crystal fibres radiating out from a centrally located common nucleus. The morphology of the building blocks of the crust at the gel reactant interface is discussed.