1304.1751 (D. Meyers et al.)

Strain mediated suppression of the metal-insulator transition in EuNiO3
thin films    [PDF]

D. Meyers, S. Middey, M. Kareev, M. van Veenendaal, E. J. Moon, B. A. Gray, J. W. Freeland, J. Chakhalian

Ultrathin epitaxial films of EuNiO3 were grown on a series of substrates traversing highly compressive (- 2.4%) to highly tensile (2.5%) lattice mismatch. X-ray diffraction measurements showed the expected c-lattice parameter shift for compressive strain, but no detectable shift for tensilely strained substrates, while reciprocal space mapping confirmed the tensile strained film maintained epitaxial coherence. Transport measurements showed a successively (from tensile to compressive) lower resistance and a complete suppression of the metalinsulator transition at highly compressive lattice mismatch. Corroborating these findings, X-ray absorption spectroscopy measurements revealed a strong multiplet splitting in the tensile samples that progressively weakens with increasing compressive strain that, combined with cluster calculations, showed enhanced covalence between Ni-d and O-p orbitals leads to the metallic state.

View original: http://arxiv.org/abs/1304.1751