Characteristics of high dielectric cubic Gd2O3 thin films deposited on cubic LaAlO3 by pulsed laser deposition

The high-kappa gadolinium oxide (Gd2O3) thin films have been prepared on LaAlO3 (LAO) surfaces using pulsed laser deposition (PLD) technique at different substrate temperatures. Cubic Gd2O3 films with preferred orientation (4 0 0) could be formed on LAO surfaces when the substrate temperature was maintained at 850 degrees C during the growth. The reflection high energy electron diffraction (RHEED) pattern showed that the lattice constant of the cubic films were in agreement with that of bulk Gd2O3. The surface morphology of the samples was investigated by atomic force microscopy (AFM). Transmission electron microscopy diffraction pattern manifested a diagonal-on-cube epitaxial relationship of Gd2O3 [1 0 0]vertical bar LAO [1 1 0] and Gd2O3 ((1) over bar 0 0)vertical bar LAO ((1) over bar 0 0). The high dielectric constant (kappa similar to 22) of cubic Gd2O3 was deduced from the characterization of capacitance-voltage (C-V). (C) 2007 Elsevier B.V. All rights reserved.