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Full-Text Articles in Physics

Magnetism Of (Dy0.5er0.5)Al2 Single Crystal In Ac And Dc Magnetic Fields, Evgenii M. Levin, Karl A. Gschneidner Jr., Thomas A. Lograsso, Deborah L. Schlagel Aug 2006

Magnetism Of (Dy0.5er0.5)Al2 Single Crystal In Ac And Dc Magnetic Fields, Evgenii M. Levin, Karl A. Gschneidner Jr., Thomas A. Lograsso, Deborah L. Schlagel

Ames Laboratory Publications

The temperature (4.2–90 K), ac magnetic field (1.25–50 Oe), frequency (5–125 Hz), and bias dc magnetic field (0–10 kOe) dependencies of the real and imaginary components of the ac magnetic susceptibility, and the temperature (4.2–250 K) and dc magnetic field(0.1–50 kOe) dependencies of the dc magnetic susceptibility and magnetization of a(Dy0.5Er0.5)Al2 single crystal have been studied. Isothermal magnetization measurement in a dc magnetic field indicates that (Dy0.5Er0.5)Al2 orders ferromagnetically at 37 K. The ac ...


Variation Of Magnetostriction With Temperature In Tb5si2.2ge1.8 Single Crystal, A. P. Ring, H. L. Ziegler, Thomas A. Lograsso, Deborah L. Schlagel, J. E. Snyder, David C. Jiles Apr 2006

Variation Of Magnetostriction With Temperature In Tb5si2.2ge1.8 Single Crystal, A. P. Ring, H. L. Ziegler, Thomas A. Lograsso, Deborah L. Schlagel, J. E. Snyder, David C. Jiles

Ames Laboratory Conference Papers, Posters, and Presentations

The Tb5(SixGe4−x) alloy system is similar to the better known Gd5(SixGe4−x), except it has a more complex magnetic and structural phase diagram. Gd5(SixGe1−x)4 has received much attention recently due to its giant magnetocaloric effect, colossal magnetostriction and giant magnetoresistance in the vicinity of a first order combined magnetic-structural phase transition. The magnetostriction changes that accompany the phase transitions of single crystal Tb5(Si2.2Ge1.8) have been investigated at temperatures between 20 and150 K by measurements of ...


Temperature Dependence Of The Magnetic Anisotropy And Magnetostriction Of Fe100−Xgax (X = 8.6, 16.6, 28.5), A. E. Clark, M. Wun-Fogle, J. B. Restorff, Kevin W. Dennis, Thomas A. Lograsso, R. William Mccallum May 2005

Temperature Dependence Of The Magnetic Anisotropy And Magnetostriction Of Fe100−Xgax (X = 8.6, 16.6, 28.5), A. E. Clark, M. Wun-Fogle, J. B. Restorff, Kevin W. Dennis, Thomas A. Lograsso, R. William Mccallum

Ames Laboratory Conference Papers, Posters, and Presentations

The temperature dependence of the lowest order magnetic anisotropy constant K1 and the lowest order saturation magnetostriction constant, (3/2)λ100, were measured from 4 K to 300 K for Fe91.4Ga8.6,Fe83.4Ga16.6, and Fe71.5Ga28.5 and were compared to the normalized magnetization power law, ml(l+1)/2. Fe91.4Ga8.6 maintains the magnetostriction anomaly of Fe (dλ100/dT>0) and K1 is a reasonable fit to the ml(l+1)/2power law with ...


Magnetic Anisotropy And Phase Transitions In Single-Crystal Tb5(Si2.2ge1.8), M. Han, J. E. Snyder, W. Tang, Thomas A. Lograsso, Deborah L. Schlagel, David C. Jiles May 2005

Magnetic Anisotropy And Phase Transitions In Single-Crystal Tb5(Si2.2ge1.8), M. Han, J. E. Snyder, W. Tang, Thomas A. Lograsso, Deborah L. Schlagel, David C. Jiles

Ames Laboratory Conference Papers, Posters, and Presentations

The Tb5(SixGe4−x) alloy system has many features in common with the Gd5(SixGe4−x)system although it has a more complex magnetic and structural phase diagram. This paper reports on the magnetic anisotropy and magnetic phase transition of single-crystalTb5(Si2.2Ge1.8) which has been investigated by the measurements of M-H and M-T along the a, b, and c axes. The variation of 1/χ vs T indicates that there is a transition from paramagnetic to ferromagnetic at Tc = 110 K. Below this ...


Magnetostriction And Elasticity Of Body Centered Cubic Fe100−Xbex Alloys, A. E. Clark, M. Wun-Fogle, J. B. Restorff, Thomas A. Lograsso, G. Petculescu Jun 2004

Magnetostriction And Elasticity Of Body Centered Cubic Fe100−Xbex Alloys, A. E. Clark, M. Wun-Fogle, J. B. Restorff, Thomas A. Lograsso, G. Petculescu

Ames Laboratory Conference Papers, Posters, and Presentations

Magnetostriction measurements from 77 K to room temperature on oriented (100) and (110) disk samples of Fe93.9Be6.1 and Fe88.7Be11.3 reveal substantial increases in λ100compared to iron. For the 11.3% alloy, λ100=110 ppm, a sixfold increase above that of α-Fe. For the 6.1% alloy, λ100=81 ppm, ∼40% and ∼170% greater than λ100 of comparable Fe–Ga and Fe–Al alloys, respectively, for H=15 kOe. Large differences exist between the values of λ100 and λ111 (λ100>0, λ111 ...


Magnetic Field Induced Phase Transitions In Gd5(Si1.95ge2.05) Single Crystal And The Anisotropic Magnetocaloric Effect, H. Tang, A. O. Pecharsky, Deborah L. Schlagel, Thomas A. Lograsso, Vitalij K. Pecharsky, Karl A. Gschneidner Jr. May 2003

Magnetic Field Induced Phase Transitions In Gd5(Si1.95ge2.05) Single Crystal And The Anisotropic Magnetocaloric Effect, H. Tang, A. O. Pecharsky, Deborah L. Schlagel, Thomas A. Lograsso, Vitalij K. Pecharsky, Karl A. Gschneidner Jr.

Ames Laboratory Conference Papers, Posters, and Presentations

Magnetization measurements using a Gd5(Si1.95Ge2.05) single crystal with the magnetic field applied along three crystallographic directions, [001], [010] and [100], were carried out as a function of the applied field (0–56 kOe) at various temperatures (∼5–320 K). The magnetic field (H)–temperature (T) phase diagrams were constructed for theGd5(Si1.95Ge2.05) single crystal with field along the three directions. A small anisotropy was observed. The magnetocaloric effect was calculated from isothermal magnetization data, and the observed anisotropy correlates with the HT phase diagrams. The results ...


Generalization Of Hysteresis Modeling To Anisotropic Materials, A. Ramesh, David C. Jiles, Y. Bi Apr 1997

Generalization Of Hysteresis Modeling To Anisotropic Materials, A. Ramesh, David C. Jiles, Y. Bi

Materials Science and Engineering Publications

An extension to the model of hysteresis has been presented earlier which included the effect of anisotropy in the modeling of the anhysteretic magnetization curves of uniaxially anisotropic single crystalline materials. Further exploration of this extension shown here considers different kinds of crystal anisotropy in materials. Theory considers that the differential susceptibility at any given field is determined by the displacement of the prevailing magnetization from the anhysteretic magnetization. Thus, it has been shown that the effect of anisotropy on magnetic hysteresis in materials can be incorporated into the model of hysteresis through the anisotropic anhysteretic. This extension is likely ...