Variation of magnetostriction with temperature in Tb5Si2.2Ge1.8 single crystal

Lograsso, Thomas
Schlagel, Deborah
Ring, A.
Ziegler, H.
Jiles, David
Lograsso, Thomas
Schlagel, Deborah
Snyder, J.
Jiles, David
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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 magnetostriction along the a axis. Over this temperature range the shape and slope of the magnetostriction curves change, indicative of changes in the magnetic state, crystal structure, and magnetic anisotropy. The results appear to indicate a phase transition that occurs near 106 K (onset-completion range of 116–100 K). The steepness of the strain transition, its unusual hysteresis, and its temperature dependence appear to indicate a first order phase transition which is activated by applied magnetic field in addition to temperature (see Fig. 1). Magnetostriction measurements at temperature below the transition region appear to indicate a magnetostriction of small overall magnitude (about 30×10−6) but high anisotropy, with anistropy showing considerable temperature dependence.

<p>Copyright 2006 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.</p> <p>The following article appeared in <em>Journal of Applied Physics</em> 99 (2006): 08R104 and may be found at <a href="" target="_blank"></a>.</p>
Materials Science and Engineering, terbium alloys, silicon alloys, germanium alloys, magnetostriction, magnetic transitions, magnetocaloric effects, giant magnetoresistance, crystal structure, magnetic anisotropy, magnetic hysteresis