Anomalous Behavior in Electrical Transport Properties in Single-Crystal Gd5Si1.8Ge2.2 and Polycrystalline Gd5Si2.09Ge1.91

作者：Hadimani R L^*; Melikhov Y; Snyder J E; Jiles D C

来源：IEEE Transactions on Magnetics, 2009, 45(10): 4368-4371.

DOI：10.1109/TMAG.2009.2024123

• Gd-5(SixGe1-x)(4)
• first-order phase transition
• magnetoresistance
• magnetocaloric effect

Gd-5(SixGe1-x)(4) exhibits anomalous behavior in resistivity measurement close to its first-order phase transition temperature. In this paper, we present a series of resistivity as a function of temperature measurements indicating an irreversible change in the resistivity. The resistivity of the sample increased every time the sample was passed through first-order phase transition for both single-crystal Gd5Si1.8Ge2.2(x = 0.45) and polycrystalline Gd5Si2.09Ge1.91(x = 0.522) Magnetic hysteresis loops were also plotted for the single-crystal Gd5Si1.8Ge2.2 at 220 K. The hysteresis loops were measured several times at 220 K, cycling the temperature between 220 and 300 K between each measurement. The coercivity of the sample increased irreversibly when the sample was passed through the first-order phase transition. The increase in the coercivity was 20 Oe for the fourth and fifth thermal cycles and then it remained constant up to 15 thermal cycles.

• 出版日期2009-10