Magneto-impedance measurements (MI) were carried out on thin-films of Cu100-xMnxAu13.5 (x = 6.75 and 13.5). The sample with × = 6.75 (13.5) undergoes a phase transition to a spin-glass state below a glass temperature of about TG = 31 K (55 K). The MI measurements were carried out for temperatures (T) from 300 K down to 5 K in applied magnetic fields in the range of ± 3.5 kOe and for an ac electric current with frequency of 9.0 MHz. Short-range interaction and spin-fluctuations yielded non-vanishing values for the MI data for all values of T. The transverse magnetic permeability (μT) was obtained for both sample compositions demonstrating that MI is a suitable technique to study canonical spin-glasses in the MHz regime. Moreover, it was observed that the spin-fluctuations in very short time scale (∼10−7 s) are important down to the lowest temperature investigated of 5 K. The transverse magnetic susceptibility, μT, showed a minimum near the freezing temperature.
Bibliographical noteFunding Information:
This work was supported in Brazil by CNPq, CAPES, FACEPE and FINEP, and in the USA by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award DE-SC0013599.
© 2021 Elsevier B.V.
- Magnetic materials