Structural Chemistry & Crystallography Communication

Interplay between H-bonding and charge ordering in Fe3(PO4)2(OH)2 barbosalite

International Conference on Applied Crystallography
October 16-17, 2017 | Chicago, USA

J Rouquette, J Haines, V Ranieri, M Poienar, A Guesdon and C Martin

Universite Montpellier, France
CRISMAT, France
Laboratoire Leon Brillouin, France

ScientificTracks Abstracts: Struct Chem Crystallogr Commun

DOI: 10.21767/2470-9905-C1-002

Abstract

Charge Ordering (CO) in transition metal oxides is an important parameter for obtaining original magnetic and/or electric properties. That was largely shown within the framework of the studies on colossal magneto-resistance in manganese perovskites and it again seems to be at the origin of the ferroelectricity in CaMn7O12 or LuFe2O4. The mixed valence of iron in the system is a particular motivation in view of the long lasting research on the understanding of the effects of pressure on charge order/magnetic order in iron compounds such as the LuFe2O4 new charge ordered state and the pressure dependence of its magnetic order. Here we focus on Fe2+Fe3+2(PO4)2(OH)2 barbosalite single crystal, an hydroxyphosphate of iron which exhibits a mixed valence state. High pressure behavior of barbosalite was successfully characterized based on single crystal X-ray diffraction, Raman and infrared spectroscopies. Fe2+Fe3+2(PO4)2(OH)2 presents two phase transition at close to 3 and 8 GPa respectively which are clearly governed by an interplay between H-bonding and electron delocalization. Moreover the temperature reaction Fe2+Fe3+2(PO4)2(OH)2+ Fe3+3(PO4)2(OOH).

Biography

J Rouquette has obtained his PhD in Julien Haines’ group in Materials Science (Condensed Matter) from University of Montpellier, France in 2004 and was a Postdoctoral Fellow in Leonid Dubrovinsky’s group at the Bayerisches Geoinstitut in Bayreuth University, Germany for two years. He has joined the CNRS as a Researcher in 2004 in the field of ferroelectrics/multiferroics and he defended his Habilitation in 2012 entitled “insitu structural studies of ferroic materials as a function of P,T,E,B. He has published more than 50 research papers in these areas.