Strain effects on ferroelectric polarization and magnetism in orthorhombic HoMnO3

Details Strain effects on ferroelectric polarization and magnetism in orthorhombic HoMnO3 Strain effects on ferroelectric polarization and magnetism in orthorhombic HoMnO3

2011-02-10

arxiv.org/abs/1102.2168v1

Physics

Condensed Matter

Materials Science

7 pages, 11 figures

Scientific paper

Aiming at increasing the ferroelectric polarization in AFM-E ortho-\hmo, we investigate the in-plane strain effects on both the magnetic configuration and the polarization by means of density functional theory calculations and model Hamiltonian approaches. Our results show that the net polarization is largely enhanced under compressive strain, due to an increase of the electronic contribution to the polarization, whereas the ionic contribution is found to decrease. We identify the electron-lattice coupling, due to Jahn-Teller (JT) distortions, and its response to strain to be responsible for the observed behavior. The JT-induced orbital ordering of occupied Mn-e$_g^1$ electrons in alternating $3x^2-r^2/3y^2-r^2$ orbital states at equilibrium changes to a mixture with $x^2-z^2/y^2-z^2$ states under in-plane compressive strain. The asymmetric hopping of e$_g$ electrons between Mn ions along zig-zag spin chains (typical of the AFM-E spin configuration) is therefore enhanced under strain, explaining the large value of the polarization. We reproduce the change in the orbital ordering pattern in a degenerate double-exchange model supplemented with electron-phonon interaction. In this picture, the orbital ordering change is related to a change of the Berry phase of the e$_g$ electrons, which in turn causes an increase of the polarization, whose origin is purely electronic.

Affiliated with

Also associated with

No associations

Rating

Strain effects on ferroelectric polarization and magnetism in orthorhombic HoMnO3 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Strain effects on ferroelectric polarization and magnetism in orthorhombic HoMnO3, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Strain effects on ferroelectric polarization and magnetism in orthorhombic HoMnO3 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-694676