Pregelj M.,Jozef Stefan Institute |
Pregelj M.,Laboratory for Neutron Scattering |
Jeschke H.O.,Goethe University Frankfurt |
Feldner H.,Goethe University Frankfurt |
And 12 more authors.
Physical Review B - Condensed Matter and Materials Physics | Year: 2012
A combination of density functional theory calculations, many-body model considerations, and magnetization and electron-spin-resonance measurements shows that the multiferroic FeTe 2O 5Br should be described as a system of alternating antiferromagnetic S=5/2 chains with strong Fe-O-Te-O-Fe bridges weakly coupled by two-dimensional frustrated interactions, rather than the previously reported tetramer model. The peculiar temperature dependence of the incommensurate magnetic vector can be explained in terms of interchain exchange striction being responsible for the emergent net electric polarization. © 2012 American Physical Society.
Jeschke H.,Goethe University Frankfurt |
Opahle I.,Goethe University Frankfurt |
Kandpal H.,Leibniz Institute for Solid State and Materials Research |
Valenti R.,Goethe University Frankfurt |
And 13 more authors.
Physical Review Letters | Year: 2011
The natural mineral azurite Cu3(CO3) 2(OH)2 is a frustrated magnet displaying unusual and controversially discussed magnetic behavior. Motivated by the lack of a unified description for this system, we perform a theoretical study based on density functional theory as well as state-of-the-art numerical many-body calculations. We propose an effective generalized spin-1/2 diamond chain model which provides a consistent description of experiments: low-temperature magnetization, inelastic neutron scattering, nuclear magnetic resonance measurements, magnetic susceptibility as well as new specific heat measurements. With this study we demonstrate that the balanced combination of first principles with powerful many-body methods successfully describes the behavior of this frustrated material. © 2011 American Physical Society.