abstract
The hyperfine interaction between the quadrupole moment of atomic nuclei and the electric field gradient (EFG) provides information on the electronic charge distribution close to a given atomic site. In ferroelectric materials, the loss of inversion symmetry of the electronic charge distribution is necessary for the appearance of the electric polarization. We present first-principles density functional theory calculations of ferroelectrics such as BaTiO3, KNbO3, PbTiO3 and other oxides with perovskite structures, by focusing on both EFG tensors and polarization. We analyze the EFG tensor properties such as orientation and correlation between components and their relation with electric polarization. This work supports previous studies of ferroelectric materials where a relation between EFG tensors and polarization was observed, which may be exploited to study the ferroelectric order when standard techniques to measure polarization are not easily applied.
keywords
QUADRUPOLE COUPLING-CONSTANTS; ROCHELLE SALT; 1ST-PRINCIPLES CALCULATION; TEMPERATURE-DEPENDENCE; SINGLE-CRYSTALS; BARIUM-TITANATE; NMR; STATE; TRANSITION; BATIO3
subject category
Physics
authors
Goncalves, JN; Stroppa, A; Correia, JG; Butz, T; Picozzi, S; Fenta, AS; Amaral, VS
our authors
João Nuno Santos Gonçalves
Junior Researcher
Vitor Brás Sequeira Amaral
Full professorProjects
MULTIFOX: Nanometric Probing and Modification of Multiferroic Oxides (PTDC/FIS/105416/2008)
acknowledgements
This work has been supported by the AQUIFER (Aquila Initiative for Ferroics) research program, sponsored by the International Center for Materials Research (ICMR) at UCSB, and research projects PTDC/FIS/105416/2008 and CERN/FP/116320/2010. J. N. Goncalves acknowledges FCT Grant No. SFRH/BD/42194/2007. The theoretical research at CNR-SPIN has received funding by the European Community's Seventh Framework Programme FP7/2007-2013 under Grant No. 203523-BISMUTH. A.S. thanks P. Barone for comments on the manuscript. Computational support by CASPUR Supercomputing center in Rome is acknowledged.