Dual Nature of Improper Ferroelectricity in a Magnetoelectric Multiferroic

Journal Article · Sun Dec 31 23:00:00 EST 2006 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.99.227201· OSTI ID:961780

Picozzi, S. ^[1]; Yamauchi, K. ^[1]; Sanyal, B. ^[2]; Sergienko, Ivan A ^[3]; Dagotto, Elbio R ^[3]

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1. CNR-INFM, L-Aquila, Italy
2. Uppsala University, Uppsala, Sweden
3. ORNL

Using first-principles calculations, we study the microscopic origin of ferroelectricity (FE) induced by magnetic order in the orthorhombic HoMnO3. We obtain the largest ferroelectric polarization observed in the whole class of improper magnetic ferroelectrics to date. We find that the two proposed mechanisms for FE in multiferroics, lattice and electronic based, are simultaneously active in this compound: a large portion of the ferroelectric polarization arises due to quantum-mechanical effects of electron orbital polarization, in addition to the conventional polar atomic displacements. An interesting mechanism for switching the magnetoelectric domains by an electric field via a 180 coherent rotation of Mn spins is also proposed.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 961780
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Vol. 99; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATOMIC DISPLACEMENTS
ELECTRIC FIELDS
ELECTRONS
FERROELECTRIC MATERIALS
POLARIZATION
ROTATION
SPIN