Mechanism of Ferroelectricity in $d^3$ Perovskites - a Model Study

Abstract

By means of a model Hamiltonian approach we study the role of volume expansion, Hund's coupling and electron correlation in the standard hybridization mechanism for ferroelectricity in cubic CaMnO${}_3$, a prototypical non-$d^0$ perovskite. Our results establish that the ferroelectric instability arises from a subtle balance between different energy contributions, explaining the origin of its enhancement under negative pressure. Expansion of volume is found to cause a strong reduction of the elastic energy, while leaving almost unchanged the tendency of Mn states to form covalent bonds with the surrounding oxygens. Hund's coupling with local spins of magnetic cations can reduce and even suppress the instability towards the ferroelectric state.

7 pages, 5 figures

References in corpus (8)

• Spin current and magneto-electric effect in non-collinear magnets
• Role of the Dzyaloshinskii-Moriya interaction in multiferroic perovskites
• Multiferroics: different ways to combine magnetism and ferroelectricity
• Ferroelectricity in the Magnetic E-Phase of Orthorhombic Perovskites
• Dual nature of improper ferroelectricity in a magnetoelectric multiferroic
• Engineering multiferroism in CaMnO${}_3$
• Non-$d^0$ Mn-driven ferroelectricity in antiferromagnetic BaMnO${}_3$
• Ferroelectricity due to orbital ordering in E-type undoped rare-earth manganites

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• Advances in ab-initio theory of Multiferroics. Materials and mechanisms: modelling and understanding
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• Tuning the Ferroelectric Polarization in $A{A}^{\prime }$MnWO${}_6$ Double Perovskites through $A$ Cation Substitution
• Jahn-Teller distortions as a novel source of multiferroicity
• Mechanisms and origin of multiferroicity
• Magnetoelectric effect arising from a field-induced pseudo Jahn-Teller distortion in a rare earth magnet