Title :
Spontaneous Magneto-Impedance in YCo12B6 and GdCo12B6 Intermetallic Compounds
Author :
Mesquita, Fabiano ; Diop, Leopold V. B. ; Fraga, Gilberto ; Isnard, Olivier ; Pureur, Paulo
Author_Institution :
Inst. de Fis., Univ. Fed. do Rio Grande do Sul, Porto Alegre, Brazil
fDate :
7/7/1905 12:00:00 AM
Abstract :
We report on electrical impedance measurements in variable temperatures and fixed frequencies in the intermetallic compounds YCo12B6 and GdCo12B6 and discuss the potential of this technique to probe intrinsic magnetic properties and magnetization dynamics. The studied temperature range that extends from 15 to 300 K encompasses the Curie temperature TC of both systems. Frequencies span the interval from 37 Hz to 1.5 MHz. Effects of magnetic ordering are observed in the impedance results. The Hopkinson effect becomes evident near TC in frequencies above 10 kHz for GdCo12B6 and above 100 kHz for YCo12B6. A qualitative analysis of these results suggests that the Hopkinson peaks in both systems result from a critical phenomenon associated with the initial permeability. In frequencies above 100 kHz, a change of slope in the impedance versus temperature curves for GdCo12B6 occurs at the compensation temperature. We conclude that the impedance measurement is a powerful technique to investigate intrinsic magnetic properties of Y-Co and Gd-Co-based compounds.
Keywords :
Curie temperature; boron alloys; cobalt alloys; gadolinium alloys; magnetic permeability; magnetisation; magnetoresistance; yttrium alloys; Curie temperature; GdCo12B6; Hopkinson effect; YCo12B6; compensation temperature; critical phenomenon; electrical impedance measurements; frequency 37 Hz to 1.5 MHz; intermetallic compounds; intrinsic magnetic properties; magnetic ordering; magnetic permeability; magnetization dynamics; spontaneous magnetoimpedance; temperature 15 K to 300 K; Compounds; Impedance; Magnetic field measurement; Magnetization; Permeability; Temperature; Temperature measurement; Hopkinson effect; Impedance; Magnetization dynamics; impedance; permeability;
Journal_Title :
Magnetics Letters, IEEE
DOI :
10.1109/LMAG.2015.2452896