Mechanism of ferroelectricity in d3 perovskites: A model study

被引：18

作者：

Barone, Paolo ^{[1
]}

Kanungo, Sudipta ^{[2
]}

Picozzi, Silvia ^{[1
]}

Saha-Dasgupta, Tanusri ^{[2
]}

机构：

[1] CNR SPIN, I-67100 Laquila, Italy

[2] SN Bose Natl Ctr Basic Sci, Kolkata 700098, India

来源：

PHYSICAL REVIEW B | 2011年 / 84卷 / 13期

关键词：

D O I：

10.1103/PhysRevB.84.134101

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

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 CaMnO3, 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. An expansion of the volume is found to cause a strong reduction in 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 toward the ferroelectric state.

引用

页数：7

共 38 条

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