First-principles study of symmetry lowering and polarization inBaTiO3∕SrTiO3superlattices with in-plane expansion

2004/11/24 by Karen Johnston, Xiangyang Huang, Jeffrey B. Neaton +1 · 1 citation
Chemistry · Materials Science · Physics and Astronomy · #Chemistry #Condensed matter physics #Crystal structure #Crystallography #Electronic and Structural Properties of Oxides #Epitaxy #Ferroelectric and Piezoelectric Materials #Lattice (music) #Materials science #Monoclinic crystal system #Multiferroics and related materials #Nanotechnology #Physical chemistry #Physics #Polarization (electrochemistry) #Superlattice #cond-mat.mtrl-sci

paper · pdf · doi:10.1103/physrevb.71.100103

4 pages, 2 figures

arxiv created 2004/11/24 · openalex publication_date 2005/03/31 · arxiv updated 2013/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

The crystal structure and local spontaneous polarization of (BaTiO₃)_m∕(SrTiO₃)_n superlattices are calculated using first-principles density-functional theory. The in-plane lattice constant is constrained to be 1% larger than the SrTiO₃ (ST) substrate to take into account the in-plane expansion observed in recent experiments. The symmetry is lowered to monoclinic space group Cm allowing for polarization along the [110] and [001] directions. The polarization component in the [110] direction is found to develop only in the SrTiO₃ layers and falls to zero in the BaTiO₃ (BT) layers, whereas the polarization in the [001] direction is approximately uniform throughout the superlattice. These findings are consistent with recent experimental data and first-principles results for epitaxially strained BT and ST.

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