AVS 50th International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI-WeP

Paper MI-WeP15
The Isomer Dependent Semiconductors of Boroncarbide

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: A.N. Caruso, University of Nebraska
Authors: A.N. Caruso, University of Nebraska
L. Bernard, Ecole Polytechnique Federale de Lausanne
B. Doudin, University of Nebraska
P.A. Dowben, University of Nebraska
Correspondent: Click to Email
We demonstrate that boroncarbide, grown by chemical vapor deposition, is an effective dielectric barrier layer for magnetic tunnel junctions. Decomposition of the insulator closo-1,2 dicarbadodecaborane or orthocarborane (C@sub 2@B@sub 10@H@sub 12@) has been shown to form p-type semiconducting boron carbide (C@sub 2@B@sub 10@).@footnote 1-4@ We present recent photoemission results which indicate that closo-1,7 dicarbadodecaborane or metacarborane (C@sub 2@B@sub 10@H@sub 12@) forms an n-type semiconducting boroncarbide (C@sub 2@B@sub 10@) upon decomposition. Bonding, orientation, and electronic structure of the two materials in both associative and decomposed configurations are compared as adsorbates. The electronic structure of orthocarborane and metacarborane are calculated to be very similar, but there are significant differences in the experimental binding energies for each isomer as an adsorbed species. Metacarborane adsorbs on both Co and Au with the Fermi Level (chemical potential) placed closer to the lowest unoccupied molecular orbital than is observed with orthocarborane adsorbed on Co and Cu. @FootnoteText@@footnote 1@ S. Lee and P.A. Dowben, Appl. Phys. A 58 (1994) 223. @footnote 2@ Dongjin Byun, Seong-don Hwang, Jiandi Zhang, Hong Zeng, F. Keith Perkins, G. Vidali and P.A. Dowben, Jap. Journ. Appl. Phys. Lett. 34 (1995) L941-L944@footnote 3@ D.N. McIlroy, C. Waldfried, T. McAvoy, Jaewu Choi, P.A. Dowben and D. Heskett, Chem. Phys. Lett. 264 (1997) 168-173@footnote 4@ Seong-Don Hwang, Ken Yang, P.A. Dowben, Ahmad A. Ahmad, N.J. Ianno, J.Z. Li, J.Y. Lin, H.X. Jiang and D.N. McIlroy, Appl. Phys. Lett. 70 (1997) 1028-1030 .