Optical absorption at its onset in sputter deposited hafnia–titania nanolaminates

Autor:	Carolyn Rubin Aita, Massiel Cristina Cisneros-Morales
Rok vydání:	2010
Předmět:	Nanocomposite Condensed matter physics biology Chemistry Band gap Bilayer Analytical chemistry General Physics and Astronomy Sputter deposition Hafnia biology.organism_classification Absorption edge Sputtering Attenuation coefficient
Zdroj:	Journal of Applied Physics. 108:123506
ISSN:	1089-7550 0021-8979
DOI:	10.1063/1.3520678
Popis:	The onset of the fundamental optical absorption edge in sputter deposited HfO2–TiO2 nanolaminate films grown on unheated substrates was investigated. Three bilayer architectures were examined, representing overall film chemistry from 0.51 to 0.72 atom fraction Hf. The goal was to determine the absorption coefficient, α(E), versus incident photon energy, E, and to model this dependence in terms of the absorption behavior of specific functional units within the nanolaminate. Persistence and amalgamation models were applied, representing the extremes of segregated cation and mixed cation structures, respectively, and both were found to be unsatisfactory. Consideration of physiochemical data for the nanolaminates led to the development of a modified persistence model for absorption. α(E) was decomposed into contributions from (I) broad (9 nm-thick) interfacial regions that were chiefly o-HfTiO4, and (II) regions remote from interfaces that contained material based on a highly defective m-HfO2 lattice. The abs...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::4e92ff8c2c49c8647191640c87681027 https://doi.org/10.1063/1.3520678 Zobrazit plný text záznamu