Carbon enters silica forming a cristobalite-type CO2-SiO2 solid solution

M. Santoro (1) , F.A. Gorelli (2) , Roberto Bini (1, 1) , Ashkan Salamat (3) , Gastón Garbarino (3) , Claire Levelut (4) , Olivier Cambon (5) , Julien Haines (5)

1 UniFI - Università degli Studi di Firenze = University of Florence = Université de Florence
2 LENS, European Laboratory for Non-linear Spectroscopy and INFM
3 ESRF - European Synchrotron Radiation Facility
4 L2C - Laboratoire Charles Coulomb
5 ICGM ICMMM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier

Relaxor ferroelectric perovskites are highly polarizable and can exhibit giant coupling between elastic strain and an applied electric field. Here, we report an in situ extended X-ray absorption fine structure (EXAFS) study of a PbZn1/3Nb2/3O3 (PZN) single crystal as a function of the electric field. We show that the strong dipoles in the NbO6 octahedra bonds are aligned along the four < 011 > directions close to the orientation of the electric field, while a small reversible polar shift occurs for Zn in the direction of the electric field, i.e., positive or negative. This reversible Zn-O polar shift is proposed to play an important role in both the "easy" switching of the ferroelectric polarization and the giant piezoelectric effect in PZN.

Domaines: Matériaux

M. Santoro, F.A. Gorelli, Roberto Bini, Ashkan Salamat, Gastón Garbarino, et al.. Carbon enters silica forming a cristobalite-type CO2-SiO2 solid solution. Nature Communications, 2014, 5, pp.3761. ⟨10.1038/ncomms4761⟩. ⟨hal-01066314⟩