Abstract
By controlling stoichiometry via a hybrid molecular beam epitaxy approach, we report on the study of thin film growth and the electronic transport properties of phase-pure, epitaxial NdTiO3/SrTiO3 heterostructures grown on (001) (La0.3Sr0.7)(Al 0.65Ta0.35)O3 (LSAT) substrates as a function of cation stoichiometry in NdTiO3. Despite the symmetry mismatch between bulk NdTiO3 and the substrate, NdTiO3 films grew in an atomic layer-by-layer fashion over a range of cation stoichiometry; however amorphous films resulted in cases of extreme cation non-stoichiometry. Temperature-dependent sheet resistance measurements were consistent with Fermi-liquid metallic behavior over a wide temperature range, but revealed a remarkable crossover from metal-to-insulator (M-I) type behavior at low temperatures for all compositions. A direct correlation between cation stoichiometry, transport behavior, and the temperature of M-I transition is established.
Original language | English (US) |
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Article number | 082109 |
Journal | Applied Physics Letters |
Volume | 104 |
Issue number | 8 |
DOIs | |
State | Published - Feb 24 2014 |