TbMnO3 films have been grown under compressive strain on (001)-oriented SrTiO3 crystals. They have an orthorhombic structure and display the (001) orientation. With increasing thickness, the structure evolves from a more symmetric (tetragonal) to a less symmetric (bulk-like orthorhombic) structure, while keeping constant the in-plane compression thereby leaving the out-of-plane lattice spacing unchanged. The domain microstructure of the films is also revealed, showing an increasing number of orthorhombic domains as the thickness is decreased: we directly observe ferroelastic domains as narrow as 4nm. The high density of domain walls may explain the induced ferromagnetism observed in the films, while both the decreased anisotropy and the small size of the domains could account for the absence of a ferroelectric spin spiral phase.
@article{arxiv.0811.3886,
title = {Epitaxial TbMnO3 thin films on SrTiO3 substrates: A structural study},
author = {C. J. M. Daumont and D. Mannix and Sriram Venkatesan and D. Rubi and G. Catalan and B. J. Kooi and J. Th. M. De Hosson and B. Noheda},
journal= {arXiv preprint arXiv:0811.3886},
year = {2009}
}
Comments
Revtex, 7 pages, two columns, 10 color figures Final version as accepted for publication in Journal of Physics: Condensed Matter-Fast track communication. Role of microstructure emphasized. Main changes: Abstract and concluding remarks modified; new Discussion section added; figure on XPS measurements removed and its analysis streamlined in experimental section