Work on ultrathin high dielectric constant nanoaluminates, by Prof. Katiyar and his collaborators, was selected as cover page of J. Appl. Phys. Lett.
Geunhee Lee, Bo-Kuai Lai, Charudatta Phatak, Ram S. Katiyar, and Orlando Auciello. Appl. Phys. Lett. 102, 142901 (2013). http://dx.doi.org/10.1063/1.4790838
The work reported here demonstrates the feasibility of controlling the dielectric properties - high dielectric constant (k) and substantially extended relaxation frequency -of thin film nanolaminates (NLs) consisting of alternating TiOx and Al2O3 sublayers with various sublayer thicknesses grown by atomic layer deposition. For 150 nm thick TiOx/Al2O3 NLs with sub-nanometer thick sublayers, few Angstrom change in sublayer thickness dramatically increases relaxation cut-off frequency by more than 3 orders of magnitude with high dielectric constant (k > 800). This unusual phenomenon is discussed in the framework of two-phase Maxwell-Wagner relaxation.