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Maclyn Compton (left) and Beth Leblance (right).
Texas State University at San Marcos, Department of Physics, RFM 3228, 601 University Drive, San Marcos, TX78666.
Maclyn Stuart Compton
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Permalloy oxide thin films were successfully grown using reactive dual ion beam sputtering using a Ni80Fe20 target. Films were deposited on substrates of glass microscope slides, SiO2/Si, and Al/Si at a deposition rate of approximately1.01 Angstroms/second. The oxygen assist beam was used to expose the substrate to a beam of molecular or atomic oxygen during deposition. Magnetic moment measurements were carried out to reveal no ferromagnetic component in the films with a saturation magnetization < 10-9 Am2. This was satisfactory since it was not expected that PyO would be ferromagnetic. It was concluded from these results that there was no metallic ferromagnetic permalloy in the PyO films.
The optical properties of PyO were determined from ellipsometric measurements. Transmission data revealed that PyO absorbs a wide range of light in the visible range, more so than NiO and FeO. The determined index of refraction can now be used in simpler optical equipment to measure film thickness without having to perform ellipsometry for every sample. It is still unclear from the ellipsometric data whether PyO is a direct or indirect semiconductor and there is evidence to suggest forbidden states in the bandgap.
Impedance spectroscopy was performed and the dielectric constant was calculated over a wide range of frequencies. The dielectric constant was found to have a maximum of 522 at 320 Hz and a minimum of 16.6 at 8 MHz for the measured frequency range. The frequency dependence is consistent with previous studies carried out on CoO-NiO mixed crystals and could be due to the presence of mobile ions, dipole orientation, and/or space charge effects.
The electrical resistivity was measured for different samples at room temperature and at different temperatures for select samples. The resistivity was found to be dependent on the oxygen flow rate and would increase for decrease of oxygen flow during deposition. This phenomena occurs in other conducting oxides prepared by reactive dual ion beam sputtering, such as indium tin oxide.[39] The temperature dependent measurements showed the familiar semiconductor resistivity dependence on temperature, ln(resistivity) ~ 1/T. At this point it is not clear whether conduction occurs in the d band, s band, or is a result of hopping. Further studies must be taken in order to determine the conduction mechanism.
Publications:
[1] Wilhelmus J. Geerts, Nelson Simpson, Maclyn S. Compton, Alan Woodall, Indium Tin Oxide thin films deposited at low temperature using Dual Ion Beam Sputtering, 6 page paper published in Mat. Res. Soc. Symp. 1699 (2014) mrss14-1699-ll05-28.
[2] Md. Abdul Ahad Talukder, Yubo Cui, Maclyn Compton, Wilhelmus Geerts, Luisa Scolfaro, Stefan Zollner, FTIR Ellipsometry study on RF sputtered Permalloy-oxide Thin Films, published in MRS Advances spring 2016. doi:10.1557/adv.2016.427.
[3] Maclyn Stuart Compton, Nelson A. Simpson, Elizabeth G. LeBlanc, Michael A. Robinson, Wilhelmus J. Geerts, "Electrical and Optical Properties of Permalloy Oxide grown by dual ion beam sputtering", 6 page paper published in Mat. Res. Soc. Symp. 1708 (2014) mrss 14-1708-VV08-01.
Oral and Poster Presentations:
[1] Elizabeth LeBlanc, Maclyn Compton, Wilhelmus Geerts "The dielectric properties of Permalloy-Oxide, poster presentation at the 2013 Wise conference, Texas State University, San Marcos.
[2] Michael Robinson, Maclyn Compton, Wilhelmus Geerts, "Optical Properties of thin Films of oxidized Ni-Fe, poster presentation at the 2013 Wise conference, Texas State University, San Marcos.
[3] Maclyn Compton, Elizabeth LeBlanc, Wilhelmus Geerts, Nelson Simpson, Michael Robinson, "The Electric, Magnetic, and Optical Characteriation of Permalloy Oxide grown by Dual-Ion Beam Sputtering", oral presentation 2014-APS March meeting, Denver.
[4] Wilhelmus Geerts, Nelson Simpson, Alan Woodall, Maclyn Compon, "The Influence of Atomic Oxygen on the figure of merit of Indium Tin Oxide thin Films grown by reactive Dual Ion Beam Sputtering", oral presentation 2014-Aps March meeting, Denver.
[5] Maclyn Stuart Compton, Nelson A. Simpson, Elizabeth G. LeBlanc, Michael A. Robinson, Wilhelmus J. Geerts, "Electrical and Optical Properties of Permalloy Oxide grown by dual ion beam sputtering", oral presentation 2014 MRS Spring meeting, San Francisco, California.
[6] Wilhelmus J. Geerts, Nelson Simpson, Maclyn S. Compton, Alan Woodall, Indium Tin Oxide thin films deposited at low temperature using Dual Ion Beam Sputtering, poster presentation 2014 MRS Spring meeting, San Francisco, California.
[7]Maclyn Compton, The Electric, Magnetic, and Optical Characterization of Permalloy Oxide grown by Dual Ion Beam sputtering, thesis Texas State University, San Marcos, Summer 2014 (thesis).
Maclyn graduated from Texas State University in August 2014 and is currently working for Intel.
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