Discovery of Fe7O9: a new iron oxide with a complex monoclinic structure.
Iron oxides are fundamentally important compounds for basic and applied sciences as well as in numerous industrial applications. In this work we report the synthesis and investigation of a new binary iron oxide with the hitherto unknown stoichiometry of Fe7O9. This new oxide was synthesized at high-pressure high-temperature (HP-HT) conditions, and its black single crystals were successfully recovered at ambient conditions. By means of single crystal X-ray diffraction we determined that Fe7O9 adopts a monoclinic C2/m lattice with the most distorted crystal structure among the binary iron oxides known to date. The synthesis of Fe7O9 opens a new portal to exotic iron-rich (M,Fe)7O9 oxides with unusual stoichiometry and distorted crystal structures. Moreover, the crystal structure and phase relations of such new iron oxide groups may provide new insight into the cycling of volatiles in the Earth's interior.
Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany.
Ryosuke
R
Sinmyo
Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany.|Laboratory of Crystallography, Universität Bayreuth, D-95447 Bayreuth, Germany.
Elena
E
Bykova
Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany.
Sergey V
SV
Ovsyannikov
Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany.
Catherine
C
McCammon
European Synchrotron Radiation Facility, BP220, F-38043 Grenoble, France.
Ilya
I
Kupenko
Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany.|Laboratory of Crystallography, Universität Bayreuth, D-95447 Bayreuth, Germany.
Leyla
L
Ismailova
Bayerisches Geoinstitut, Universität Bayreuth, D-95440 Bayreuth, Germany.
Leonid
L
Dubrovinsky