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University of Nebraska - Lincoln

Si-Hwang Liou Publications

1991

Articles 1 - 6 of 6

Full-Text Articles in Physics

The Process-Controlled Magnetic Properties Of Nanostructured Co/Ag Composite Films, Sy_Hwang Liou, S. Malhotra, Z.S. Shan, David J. Sellmyer, S. Nafis, John A. Woollam, C.P. Reed, R.J. Deangelis, G.M. Chow Nov 1991

The Process-Controlled Magnetic Properties Of Nanostructured Co/Ag Composite Films, Sy_Hwang Liou, S. Malhotra, Z.S. Shan, David J. Sellmyer, S. Nafis, John A. Woollam, C.P. Reed, R.J. Deangelis, G.M. Chow

Si-Hwang Liou Publications

Nanostructured Co/Ag composite films were prepared by magnetron sputtering using a single target. The average crystallite sizes of Co and Ag in the films depend on the deposition conditions. As the substrate temperature increases from 100 °C to 600 °C, the average Ag crystallite size increases from 39 to 452 Å, and the average Co crystallite size increases from Å in the film with 39 vol. % of Co. The films with 39 vol. % of Co and prepared at 400 °C substrate temperature showed a maximum magnetic coercivity of 565 Oe at 6 K. We have studied the correlation between ...


Temperature And Layer-Thickness Dependencies Of Kerr Rotation In Dy/Co Multilayers, Z.S. Shan, J.X. Shen, Roger D. Kirby, Sy_Hwang Liou, David J. Sellmyer Nov 1991

Temperature And Layer-Thickness Dependencies Of Kerr Rotation In Dy/Co Multilayers, Z.S. Shan, J.X. Shen, Roger D. Kirby, Sy_Hwang Liou, David J. Sellmyer

Si-Hwang Liou Publications

Amorphous Dy/Co multilayers with the individual layer thickness between 4 and 10 Å in steps of 0.5 to 1 Å were studied systematically over the temperature range 100–300 K. The Kerr rotation increases as temperature decreases, or as Co content increases and the coercivity increases both in the low temperature region and in the vicinity of the compensation point. These characteristics were analyzed in terms of simple models of the magnetic structure and magnetization reversal.


Sputtering Pressure Effect On Microstructure Of Surface And Interface, And On Coercivity Of Co/Pt Multilayers, Ping He, William A. Mcgahan, S. Nafis, John A. Woollam, Z.S. Shan, Sy_Hwang Liou, F. Sequeda, T. Mcdaniel, H. Do Nov 1991

Sputtering Pressure Effect On Microstructure Of Surface And Interface, And On Coercivity Of Co/Pt Multilayers, Ping He, William A. Mcgahan, S. Nafis, John A. Woollam, Z.S. Shan, Sy_Hwang Liou, F. Sequeda, T. Mcdaniel, H. Do

Si-Hwang Liou Publications

Thin Co/Pt multilayers were prepared on Si and glass substrates by sputtering with Ar pressures ranging from 2.5 to 15 mTorr. The bilayer structure of the samples was Co(3 Å)/Pt(15 Å)×17, and all samples had the easy axis of magnetization perpendicular to the sample surface as determined with a SQUID magnetometer. All samples retained the layered structure, as revealed by low-angle x-ray diffraction. In addition, diffraction peaks due to the formation of Co-Pt compounds (presumably at the interfaces between Co and Pt) were identified. The coercivity of samples changed from about 400 Oe for ...


Effect Of Interfacial Microstructure On Magnetic Properties Of Dysprosium Multilayers, Z.S. Shan, B. Jacobsen, Sy_Hwang Liou, David J. Sellmyer Apr 1991

Effect Of Interfacial Microstructure On Magnetic Properties Of Dysprosium Multilayers, Z.S. Shan, B. Jacobsen, Sy_Hwang Liou, David J. Sellmyer

Si-Hwang Liou Publications

Nanostructured multilayers of Dy/M (M=Ta, Cu, Y, and Co) have been investigated. Correlations between the microstructure and the magnetic properties, in particular the effects of interfacial structure, are discussed. The temperature and layer-thickness dependences of anisotropy of these Dy/M multilayers can be interpreted reasonably in light of the model previously developed for the perpendicular anisotropy in amorphous multilayers.


The Process-Controlled Magnetic Properties In Nanostructured Fe/Ag Composite Films, Y.Z. Zhang, Sy_Hwang Liou, R.J. Deangelis, K.W. Lee, C.P. Reed, A. Nazareth Apr 1991

The Process-Controlled Magnetic Properties In Nanostructured Fe/Ag Composite Films, Y.Z. Zhang, Sy_Hwang Liou, R.J. Deangelis, K.W. Lee, C.P. Reed, A. Nazareth

Si-Hwang Liou Publications

Nanostructured Fe/Ag composite films were prepared by magnetron sputtering using a single target. Correlations between the microstructure and magnetic properties, in particular the effects of cluster-size distribution in the films, are discussed. The cluster-size distribution was calculated by analyzing the width and shape of the x-ray-diffraction peaks. The average cluster size in the films increased from 42 to 295 Å and from 38 to 320 Å in the systems of 41 and 27 vol % of Fe, respectively, as the substrate temperature increased from 100 to 500 °C. The maximum magnetic coercivity, as high as 900 Oe, has been observed ...


Synthesis And Superconducting Properties Of Tl-Ba-Ca-Cu-O Films, Sy_Hwang Liou, V.K. Chan, F. Foong, W.Y. Lee, Y.S. Gou, T.M. Uen Mar 1991

Synthesis And Superconducting Properties Of Tl-Ba-Ca-Cu-O Films, Sy_Hwang Liou, V.K. Chan, F. Foong, W.Y. Lee, Y.S. Gou, T.M. Uen

Si-Hwang Liou Publications

Tl-Ba-Ca-Cu-O superconducting films were synthesized by sputtering either from a single target or from two oxide targets in a symmetric configuration. Films were zero resistance Tc of up to 122 K were obtained after various postannealing treatments at 870-950°C under an oxygen atmosphere. The composition of the films is not very homogeneous on the submicrometer scale. The critical current of these films at 77 K is in the 103-A/cm2-104-A/cm2 range, which is much smaller than that of films prepared on SrTiO3 and LaAlO3 substrates. The low critical current density ...