Synthesis, structure, magnetic susceptibility and Mössbauer and raman spectroscopies of the new oxyphosphate Fe0.50TiO(PO4)

• Published in: Journal of solid state chemistry Vol. 179; no. 12; pp. 3709 - 3717
• Main Authors: BENMOKHTAR, S, EL JAZOULI, A, CHAMINADE, J. P, GRAVEREAU, P, WATTIAUX, A, FOURNES, L, GRENIER, J. C, WAAL, D
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier 01.12.2006
• Subjects: Chemical Sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Magnetic properties and materials; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Material chemistry; Mössbauer effect; other γ-ray spectroscopy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.); Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Raman spectra; Rietveld method; Moessbauer effect; Space groups; Ternary alloys; Moessbauer spectroscopy; X-ray diffraction; Magnetic measurements; Iron; XRD; Magnetic susceptibility; Actinides; Synthesis; Crystallographic site; Titanium; Magnetic structure; Ion exchange; Crystal structure; Long chain; X-ray spectra; Monoclinic lattices; Raman spectroscopy; Magnetic measurement; High spin states; Transition elements; Solid state reaction; Mössbauer spectroscopy; Nickel; Oxyphosphate; Inorganic compounds
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2006.08.004

A new iron titanyl oxyphosphate Fe0.50TiO(PO4) was synthesized by both solid-state reaction and Cu2+–Fe2+ ion exchange method. The material was then characterized by X-ray diffraction, Mössbauer spectroscopy, magnetic susceptibility measurements and Raman spectroscopy. The crystal structure of the compound was refined, using X-ray powder diffraction data, by Rietveld profile method; it crytallizes in the monoclinic system, space group P21/c (No.14), with a=7.4039 (3) Å, b=7.3838 (3) Å, c=7.4083 (3) Å, B=120.36° (1); V=349.44 (2) Å 3 and Z=4. The volume of the title compound is comparable to those of the M0.50IITiO(PO4) series, where MII=Mg, Co, Ni and Zn. The framework is built up from [TiO6] octahedra and [PO4] tetrahedra. [TiO6] octahedra are linked together by corners and form infinite chains along the c-axis. Ti atoms are displaced from the center of octahedral units showing an alternating short distance (1.73 Å) and a long one (2.22 Å). These chains are linked together by [PO4] tetrahedra. Fe2+ cations occupy a triangle-based antiprism sharing two faces with two [TiO6] octahedra. Mössbauer and magnetic measurements show the existence of iron only in divalent state, located exclusively in octahedral sites with high spin configuration (t2g4eg2). Raman study confirms the existence of Ti–O–Ti chains.