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Synthesis and physicochemical characterizations of a new valence-mixed pyrophosphate: Cu0.5Zn0.5Fe2(P2O(7))(2)
Authors: Lamsaf, H.; Oulmekki, A.; Elghadraoui, E. H.; Fausto, R.; Costa, B. F. O.
Ref.: J. Phys. Chem. Solids 119, 122-125 (2018)
Abstract: A new valence-mixed iron(III)-zinc(II)-copper(II) pyrophosphate, Cu-0.5(2+) Zn-0.5(2+) Fe-2(3+)(P2O74-)(2), has been synthesized by a dry-way method and structurally characterized by several techniques. The powder diffraction pattern of the new material shows that the pyrophosphate is isostructural with the iron(III)-iron(II) pyrophosphate Fe2+Fe23+(P2O74-)(2), crystallizing in an orthorhombic arrangement in the Pnma space group. Cu2+ Fe-2(3) (P2O74-)(2) was formed as a secondary phase, as determined both by X-ray diffraction and Mossbauer spectroscopy. Mossbauer spectroscopy and magnetometry measurements showed that Cu0.5Zn0.5Fe2(P2O7)(2) is paramagnetic at room temperature and the iron ions are in octahedral coordination. Neel temperature is about 3 K. Infrared and Raman spectroscopies were also used in this study to characterize the new pyrophosphate.