Journal of magnetism and magnetic materials vol:240 issue:1-3 pages:501-503
The magnetic field and temperature dependence of the low-frequency (f < 10(4) Hz) in- and out-of-phase magnetic response of antiferromagnetically coupled Fe/Cr(1 0 0) shows that at T > 100 K both the real (chi') and imaginary (chi") parts of the susceptibility exhibit hysteretic dependence on the magnetic field with maxima of chi"(H) at H approximate to +/-25 Oe. At T = 2 K the losses exhibit an unusual strong frequency dependence describable within a single relaxation time scheme. The corresponding relaxation time proves to be strongly field-dependent which could be related to some quantum tunneling processes at low temperatures. (C) 2002 Elsevier Science B.V. All rights reserved.