Structural Refinement of Nd[Fe(CN)6].4 H2O and Study of NdFeO3 Obtained by its Oxidative Thermal Decomposition at Very Low Temperatures

M. CAROLINA NAVARRO; ELISA V. PANNUNZIO-MINER; SILVINA PAGOLA; M. INÉS GÓMEZ; RAÚL E. CARBONIO

Academic Press

Lugar: San Diego (CA), USA; Año: 2005 vol. 178 p. 847 - 847

p class="MsoNormal" style="text-align: justify; line-height: 200%; margin: 0cm 0cm 0pt;">The crystal structure of Nd[Fe(CN)6].4H2O has been refined by Rietveld analysis using high resolution synchrotron powder Xray diffraction data. It belonged to the orthorhombic crystal system, Cmcm space group, with cell parameters: a = 7.473952(1) Å; b = 12.919104(2) Å and c = 13.800549(2) Å. The change in space group from P63/m which is observed in the pentahydrates (LnFe(CN)6.5H2O) to Cmcm in the tetrahydrates has been analyzed to be a consequence of the change in 9-fold coordination of Nd3+ in the pentahydrates to 8-fold coordination in the tetrahydrates, which changes the Nd3+ environment from tricapped trigonal prism to a distorted tricapped trigonal prism or square antiprism. Its decomposition process in air to produce NdFeO