On the synthesis, characterization and magnetic properties of two new phases discovered in the PbO–Fe{sub 2}O{sub 3}–P{sub 2}O{sub 5} system

Journal Article · Sat Jun 15 00:00:00 EDT 2013 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2013.03.011· OSTI ID:22306318

El Hafid, Hassan ^[1]; Velázquez, Matias ^[1]; Pérez, Olivier ^[2]; El Jazouli, Abdelaziz ^[3]; Pautrat, Alain ^[2]; Decourt, Rodolphe ^[1]; Véron, Emmanuel ^[4]; Viraphong, Oudomsack; Delmas, Claude ^[1]

---

1. CNRS, Université de Bordeaux, ICMCB, 87 avenue du Dr. A. Schweitzer, 33608 Pessac cedex (France)
2. Laboratoire de Cristallographie et Sciences des Matériaux, UMR 6508 CNRS/Université de Caen, 6 Boulevard du Maréchal Juin, 14050 Caen cedex 04 (France)
3. Laboratoire de Chimie des Matériaux Solides, URAC 17, Université Hassan II Mohammedia, Faculté des Sciences Ben M'Sik, Casablanca (Morocco)
4. Conditions Extrêmes et Matériaux: Haute Température et Irradiation, CEMHTI-CNRS UPR 3079, 1D avenue de la Recherche Scientifique, 45071 Orléans cedex 2 (France)

The PbFe{sub 3}O(PO{sub 4}){sub 3} powder compound was studied by means of X-ray diffraction (XRD) from 300 to 6 K, electron-probe microanalysis (EPMA) coupled with wavelength dispersion spectroscopy (WDS), calorimetric (DSC and specific heat) and magnetic properties measurements. Magnetization, magnetic susceptibility and specific heat measurements carried out on PbFe{sub 3}O(PO{sub 4}){sub 3} powders firmly establish a series of three ferromagnetic (FM)-like second order phase transitions spanned over the 32–8 K temperature range. Discrepancies between magnetization and specific heat data obtained in PbFe{sub 3}O(PO{sub 4}){sub 3} powders and single crystals are highlighted. A first extraction of the critical exponents (β,γ,δ) was performed by ac magnetic susceptibility in both PbFe{sub 3}O(PO{sub 4}){sub 3} powders and single crystals and the values were found to be consistent with mean-field theory. Further exploration of the PbO–Fe{sub 2}O{sub 3}–P{sub 2}O{sub 5} system led to the discovery of a new langbeinite phase, Pb{sub 1.5}Fe{sub 2}(PO{sub 4}){sub 3}, the crystal structure of which was solved by room temperature single crystal XRD (P2{sub 1}3, Z=4, a=9.7831(2) Å). This phase does not undergo any structural phase transition down to 6 K nor any kind of long range ordering down to 2 K. - Graphical abstract: Three ferromagnetic-like phase transitions discovered in the new compound PbFe{sub 3}O(PO{sub 4}){sub 3} by specific heat and ZFC/FC magnetization measurements. - Highlights: • Three FM-like second order phase transitions in PbFe{sub 3}O(PO{sub 4}){sub 3} powders. • Critical exponents (β,γ,δ) in PbFe{sub 3}O(PO{sub 4}){sub 3} consistent with mean-field behavior. • Discovery of a new langbeinite phase, Pb{sub 1.5}Fe{sub 2}(PO{sub 4}){sub 3}.

• OSTI ID: 22306318
• Journal Information: Journal of Solid State Chemistry, Vol. 202; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CALORIMETRY
CUBIC LATTICES
ELECTRON MICROPROBE ANALYSIS
EXTRACTION
FERRIMAGNETISM
FERRITES
IRON OXIDES
LEAD OXIDES
MAGNETIC SUSCEPTIBILITY
MAGNETIZATION
MEAN-FIELD THEORY
MONOCRYSTALS
PHASE TRANSFORMATIONS
PHOSPHATES
POWDERS
RAMAN SPECTROSCOPY
SPECIFIC HEAT
SYNTHESIS
WAVELENGTHS
X-RAY DIFFRACTION