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Series

1990

Peter Dowben Publications

Articles 1 - 9 of 9

Full-Text Articles in Physics

Laser Cvd And Plasma Cvd Of Cro2 Films And Cobalt Doped Cro2 Films Using Organometallic Precursors, Peter A. Dowben, Marshall Onellion Dec 1990

Laser Cvd And Plasma Cvd Of Cro2 Films And Cobalt Doped Cro2 Films Using Organometallic Precursors, Peter A. Dowben, Marshall Onellion

Peter Dowben Publications

Chromium dioxide is deposited as a ferromagnetic layer onto selected portions of a substrate or over the entire substrate. Chromium hexacarbonyl vapor is introduced into a vacuum deposition chamber at e.g. 10 milliTorr and oxygen is introduced at e.g. 15 to 100 milliTorr. A UV laser beam is focused onto the substrate to form the CrO2 layer photolytically. The CrO2 layer can also be deposited by RF plasma deposition. This technique can also be employed for depositing MoC2, WC2, Mo2φ3, MoO2 or WO2. Magnetic recording or memory devices are …


Synchrotron Radiation Induced Chemical Vapor Deposition Of Thin Films From Metal Hexacarbonyls*, Derrick C. Mancini, Shikha Varma, John K. Simons, Richard A. Rosenberg, Peter A. Dowben Nov 1990

Synchrotron Radiation Induced Chemical Vapor Deposition Of Thin Films From Metal Hexacarbonyls*, Derrick C. Mancini, Shikha Varma, John K. Simons, Richard A. Rosenberg, Peter A. Dowben

Peter Dowben Publications

We have studied the initial stages of synchrotron radiation [SR] induced chemical vapor deposition [CVD] of metal-containing thin films from metal hexacarbonyl gases. We have measured the dependence of the initial deposition rate upon gas pressure at room temperature. Substrates were exposed to SR for single fills of the electron storage ring at constant pressure of Mo(CO)6, Cr(CO)6, or W(CO) 6 gas. Deposition was monitored in situ by Auger electron spectroscopy using the SW as the excitation source. The presence of metal, carbon, and oxygen in the deposited films was observed, and the results are consistent …


Deposition Of Boron-Containing Films From Decaborane, James T. Spencer, Peter A. Dowben, Yoon G. Kim Sep 1990

Deposition Of Boron-Containing Films From Decaborane, James T. Spencer, Peter A. Dowben, Yoon G. Kim

Peter Dowben Publications

Depopsition of a boron nitride film is carried out by introducing decaborane and dry nitrogen or ammonia into a plasma-assisted chemical vapor deposition chamber. The nitrogen or ammonia partial pressure should provide an excess over the decarborane pressures for example 200 milliTorr of N2 or NH3 and 50 MilliTorr of B10H14. Other film layers can also be produced starting from decaborane.


Fabrication Of Ferromagnetic And Antiferromagnetic Chromium Oxides By Organometallic Chemical Vapor Deposition, Peter A. Dowben, Yoon Gi Kim, S. Baral-Tosh, G.O. Ramseyer, Chanyong Hwang, M. Onellion May 1990

Fabrication Of Ferromagnetic And Antiferromagnetic Chromium Oxides By Organometallic Chemical Vapor Deposition, Peter A. Dowben, Yoon Gi Kim, S. Baral-Tosh, G.O. Ramseyer, Chanyong Hwang, M. Onellion

Peter Dowben Publications

We have been able to fabricate CrO2 and Cr2O3 from ultraviolet photolytic and plasma-assisted decomposition of Cr(CO) 6 in an oxygen carrier gas. The composition of these films is uniform in composition and contains little contamination. Using magneto-optic Kerr effect measurements, we have been able to demonstrate that the CrO2 films are ferromagnetic.


The Chemistry Of The Gadolinium-Nickel Interface, D. Lagraffe, Peter A. Dowben, M. Onellion May 1990

The Chemistry Of The Gadolinium-Nickel Interface, D. Lagraffe, Peter A. Dowben, M. Onellion

Peter Dowben Publications

Gadolinium overlayers on Ni(111) have been studied by angle resolved photoemission, angle resolved AES, LEED, and RHEEB. We have observed pronounced interdiffusion of nickel with the gadolinium overlayer at temperatures as low as 150 K. This is in marked contrast with gadolinium overlayers on Cu(108) where substantial interdiffusion is not observed until 360 K, but is consistent with studies of ytterbium on nickel. [A. Nilsson, B Eriksson, N. Martenssom, J. N. Andersen, and J. Onsgaard, Phys. Rev. B 38,10357, ( 1988) and I. Chorkendorff, K. Onsgaard, J. Schmidt-May and R. Nyholm, Surf. Sci. 160, 587, (1985) .] There is a …


Ordering Of Metal Overlayers On Metal Substrates Studied Using Atom Beam Scattering, G. Vidali, C.W. Hutchings, Peter A. Dowben, M. Karimi, C. Moses, M. Foresti May 1990

Ordering Of Metal Overlayers On Metal Substrates Studied Using Atom Beam Scattering, G. Vidali, C.W. Hutchings, Peter A. Dowben, M. Karimi, C. Moses, M. Foresti

Peter Dowben Publications

We will illustrate how atom beam scattering (ABS) can be used to study the growth and ordering of adsorption of Hg on Cu(001). At low coverage (less than 2% of a monolayer), we obtain that the scattering cross section of He with (adsorbed) Hg is about 50 Å2. We find that mercury forms two stable phases on Cu(001) in the temperature range between 200 and 330 K, a c (2 x 2) and a high density c (4 x 4) phase. From ABS diffraction data, we can deduce the corrugation of the surface electron charge density of the …


The Effect Of Lateral Interactions On The Thermal Desorption Of N2 From Ni(100), Shikha Varma, Peter A. Dowben May 1990

The Effect Of Lateral Interactions On The Thermal Desorption Of N2 From Ni(100), Shikha Varma, Peter A. Dowben

Peter Dowben Publications

We have investigated the desorption of N2 from Ni(100) using thermal desorption spectroscopy (TDS). A modified Polanyi-Wigner equation has been used to obtain the desorption energy and the preexponential factor, both of which depend on the coverage of the adsorbate. We show that there is a large lateral interaction among the adlayer molecules when N2 goes down as ordered c (2 X 2) on Ni. In addition, the overlayer ordering, in the thermal desorption process, is observed to affect the thermal desorption spectra.


Selective Area Deposition Of Conducting Palladium Films On Polyimide Resins, Yoon-Gi Kim, S. Bialy, R.W. Miller, J.T. Spencer, Peter A. Dowben, Saswati Datta May 1990

Selective Area Deposition Of Conducting Palladium Films On Polyimide Resins, Yoon-Gi Kim, S. Bialy, R.W. Miller, J.T. Spencer, Peter A. Dowben, Saswati Datta

Peter Dowben Publications

We have demonstrated that the selective area deposition of palladium on polyimide substrates i s possible through the U.V. photolysis of (π - a l l y 1) (π –cyclopentadieny1) palladium. This photolytic deposition process did not result in any apparent damage to either the Ultem 1000 (polyetherimide) or Kapton substrates (polyimide substrates). The resistivity of the palladium films (< 0.1 um) suggests that the films are porous.


Magnetic Ordering Of Tb Overlayers On Ni(Ll1), D. Lagraffe, A. Miller, Peter A. Dowben, M. Onellion May 1990

Magnetic Ordering Of Tb Overlayers On Ni(Ll1), D. Lagraffe, A. Miller, Peter A. Dowben, M. Onellion

Peter Dowben Publications

The 5p3/2 to 5p1/2 shallow core level branching ratios in different - photoemission geometries provide a measure of the magnetic ordering in rare earth overlayers as a result of final state effects in photoemission. This 5p level anisotropy can be used to probe magnetic ordering across the Tb Curie temperature as well as magnetic ordering induced by a ferromagnetic substrate in Results are shown for paramagnetic Tb overlayers on Ni(111). The Ginsberg-Landau theory can be used to accurately model terbium thin films for T>Tc.