Julian Heicklen

Bio: Julian Heicklen is an academic researcher from University of Minnesota. The author has contributed to research in topics: Sign (mathematics) & Redundancy (engineering). The author has an hindex of 2, co-authored 2 publications receiving 55 citations.

Vibrational spectrum of hydrogenated amorphous SiC films

Abstract: Infrared absorption spectra are presented of amorphous Si1−xCx films made by the glow discharge process. Four bands, representing the stretching modes of SiH, CH, and SiC, and the wagging mode of SiCH3, were followed over the entire alloy composition range. It is shown that the compositional dependence of these bands varies in a manner predicted by a model in which Si and C atoms are randomly distributed throughout the film without chemical ordering. The bonded hydrogen content in the films is estimated to be of the order of 20 to 30 at%, depending on composition, with the silicon atoms bonding to a single hydrogen and the carbons bonding predominantly as CH2 and CH3 groups. Infrarotabsorptionsspektren von amorphen Si1−xCx-Schichten werden mitgeteilt, die durch einen Glimmentladungsprozes hergestellt wurden. Vier Banden, die die Streckungsmoden von SiH, CH, SiC und die „wagging”-Mode von SiCH3 darstellen, lassen sich uber den gesamten Zusammensetzungsbereich der Legierung verfolgen. Es wird gezeigt, das die Zusammensetzungsabhan gigkeit dieser Banden durch ein Modell vorhergesagt wird, in dem die Si- und C-Atome statistisch in der gesamten Schicht ohne chemische Ordnung verteilt sind. Es wird gefunden, das der Anteil an gebundenem Wasserstoff in den Schichten die Grosenordnugn von 20 bis 30 At% hat, je nach Zusammensetzung, wobei die Siliziumatome an isoliertem Wasserstoff gebunden und die Kohlenstoffatome vorwiegend als CH2− und CH3−Gruppen gebunden sind.

Infrared Intensity Sum Rule and Effective Charges

Abstract: By using a Cartesian coordinate system, it is shown that the sum of integrated infrared intensities is given by a very simple expression that depends upon atomic masses, effective charge parameters, and the molecular dipole moment, but is otherwise independent of molecular geometry. The application of this sum rule to the analysis of the intensities of the hydrocarbons reveals that the effective charge parameters are approximately transferable from one molecular system to another, with the possible exception of acetylene.

Integrated Intensities of Absorption Bands in Infrared Spectroscopy

Abstract: (1967). Integrated Intensities of Absorption Bands in Infrared Spectroscopy. Applied Spectroscopy Reviews: Vol. 1, No. 1, pp. 29-98.

Vibration—Rotation Spectra of CH4 and CD4 Impurities in Xenon, Krypton, and Argon Crystals

Abstract: The infrared spectra of CH4 and CD4, present as substitutional impurities in crystals of argon, krypton, and xenon, were studied at temperatures ranging from 5° to 40°K.Both v3 and v4 of CH4 in xenon showed a simple four line pattern which is consistent with that expected for a slightly hindered rotor. In krypton and argon a fifth line appeared on v3, as expected from King's theoretical calculations for a tetrahedral rotor in an octahedral field. In addition, argon showed absorption due to pairs or higher aggregates of CH4 molecules.The rotational spectrum of CD4 is much more highly perturbed. Detailed assignments to hindered rotational levels could not be made but the general features are in accord with King's model.The frequencies of the CH4 and CD4 absorption bands increase steadily in going from xenon to krypton to argon. This can be accounted for by the decrease in the sizes of the cavities occupied, with corresponding larger repulsive interactions between the CH4 or CD4 and the host atoms.