title: Phase stability in ferroelectric bismuth titanate: a first-principles study.
abstract: Experimental data on the structure of ferroelectric oxide bismuth titanate suggest two different kinds of structures, i.e. orthorhombic and monoclinic. Density-functional-theory-based (DFT) first-principles calculations have been performed to determine the most stable structure of bismuth titanate among experimentally observed structures. Orthorhombic and monoclinic phases are optimized to zero pressure and lattice parameters were determined as a=5.4370, b=5.4260, c=32.6833 A and Z=4 for the structure with space group B2cb, and a=5.4289, b=5.4077, c=32.8762 A, beta=90.08 degrees and Z=4 for the structure with space group B1a1. Static and relaxation calculations show that the monoclinic structure with space group B1a1 is the most stable structure.
authors.affiliation: Department of Materials and Metallurgical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India.
authors.forename: Anurag
authors.initials: A
authors.lastname: Shrinagar
authors.forename: Ashish
authors.initials: A
authors.lastname: Garg
authors.forename: Rajendra
authors.initials: R
authors.lastname: Prasad
authors.forename: Sushil
authors.initials: S
authors.lastname: Auluck