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Search Publications by: Robert D. Shull (Assoc)

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Displaying 51 - 75 of 188

Influence of Pt spacer thickness on the domain nucleation in ultrathin Co/Pt/Co trilayers

May 1, 2013
Author(s)
Robert D. Shull, Yury Y. Iunin, Y. P. Kabanov, Valerian I. Nikitenko, O. V. Skryabina, C. L. Chien
The effect of varying the interlayer coupling between two 0.6 nm thick Co layers with perpendicular anisotropy on their magnetic ground state and the domain nucleation processes during a field reversal was studied. A surprising transition from out-of-plane

Ferri- to ferro-magnetic transition in the martensitic phase of a Heusler alloy

September 15, 2012
Author(s)
Robert D. Shull, Lawrence H. Bennett, Virgil Provenzano, Y. N. Jin, Igor Levin, E. Della Torre
During the past decade the magnetic properties of Heusler alloys have been extensively studied, motivated in part by the observation of large magnetocaloric effect (MCE) peaks displayed by these alloys near room temperature. We present new data and

Controlling High Coercivities of Ferromagnetic Nanowires Encapsulated in Carbon Nanotubes

June 15, 2010
Author(s)
Robert D. Shull, Cindi L. Dennis, A. Morelos-Gomez, Florentino N. Lopez-Urias, Emilio N. Munoz-Sandoval, H. Terrones, M. Terrones
Cylindrical ferromagnetic nanowires encapsulated inside multiwalled carbon nanotubes (MWNTs) are synthesized by pyrolizing either ferrocene powder or ferrocene-toluene mixtures. By changing the way the precursor is thermolyzed, we have been able to control

Clifford Glenwood Shull

March 31, 2010
Author(s)
Robert D. Shull
In 1975 Clifford Glenwood Shull was elected to membership in the National Academy of Science. He had earlier, 1956, been admitted to the American Academy of Arts and Sciences, and would in 1994 be awarded the Nobel Prize in Physics. These and other honors

Direct Measurement of the Magnetocaloric Effect in Gd_5}Si_2}Ge_1.9}Ga_0.1}

March 19, 2010
Author(s)
E. N. Palacios, G. F. Wang, R. Burriel, Virgil Provenzano, Robert D. Shull
Doping with some metals (Fe, Cu, Ga, Mn, Al) reduces or removes the strong thermal hysteresis in the giant magnetocaloric alloys Gd_5}Si_x}Ge_1-x}_4}. We present heat capacity and direct measurements of the isothermal entropy change, ¢ST , and adiabatic

Vertically Graded Anisotropy in Co/Pd Multilayers

March 8, 2010
Author(s)
Brian J. Kirby, Joseph E. Davies, Kai Liu, Shannon Watson, G. T. Zimanyi, Robert D. Shull, Paul A. Kienzle, Julie A. Borchers
It has been theoretically predicted that depth-grading the magnetic anisotropy in perpendicular magnetic media should reduce the field required to write data, without affecting the thermal stability. To study this prediction, we have produced a series of

Magnetic Properties of Zr_(9)Ni_(11)Intermetallic Compound

February 7, 2010
Author(s)
Virgil Provenzano, Robert D. Shull, Richard M. Waterstrat, Lawrence H. Bennett, Edward Della Torre, H. Seyoum
We report on a very interesting magnetic behavior in the intermetallic compound Zr_(9)Ni_(11), namely, (i) spin-glass behavior and (ii) fluctuations in magnetization versus temperature curves. The magnetic properties are consistent with structural results

Frustrated magnetization reversal in Co/Pt multilayer films

July 13, 2009
Author(s)
Joseph E. Davies, O Hellwig, Eric E. Fullerton, M. Winklhofer, Robert D. Shull, Kai Liu
The magnetization reversal behavior in Co/Pt multilayers with perpendicular anisotropy are studied by the first order reversal curve (FORC) method. In addition to the previously observed three stage reversal process where domains first nucleate, then

Probing the Growth and Aging of Colloidal Cobalt Nanoparticles

June 11, 2009
Author(s)
Guangjun Cheng, Cindi L. Dennis, Robert D. Shull, Angela R. Hight Walker
We have combined transmission electron microscopy (TEM) and magnetic measurements to characterize the growth of colloidal cobalt (Co) nanoparticles during synthesis and their subsequent stability in air. During the growth, TEM measurements have shown the

Dipolar Chains formed by synthesized cobalt nanocubes

May 11, 2009
Author(s)
Guangjun Cheng, Robert D. Shull, Angela R. Hight Walker
Cobalt nanocubes with an average edge length of 50 nm and the epsilon crystalline structure were synthesized via thermo-decomposition in 1,2-dichlorobenzene at 120 oC in the presence of the surfactants. These nanocubes form dipolar chains upon drying in

In-plane bias in a patterned ferromagnetic/antiferromagnetic bilayer

April 30, 2009
Author(s)
Yury P. Kabanov, Valerian I. Nikitenko, Oleg A. Tikhomirov, William F. Egelhoff Jr., Alexander J. Shapiro, Robert D. Shull
Exchange bias in bi- and multilayer magnetic systems is usually ascribed to the existence of transient magnetic structures at the interfaces between adjacent layers. Here, we report the observation of a similar phenomenon in the lateral direction