Temperature-dependent magnetization reversal in exchange bias NiFe/IrMn/NiFe structures

Abstract

We demonstrate the magnetization reversal features in NiFe/IrMn/NiFe thin-film structures with 40% and 75% relative content of Ni in Permalloy in the temperature range from 80 K to 300 K. At the descending branches of the hysteresis loops, the magnetization reversal sequence of the two ferromagnetic layers is found to depend on the type of NiFe alloy. In the samples with 75% relative content of Ni, the bottom ferromagnetic layer reverses prior to the top one. On the contrary, in the samples with 40% of Ni, the top ferromagnetic layer reverses prior to the bottom one. These tendencies of magnetization reversal are preserved in the entire range of temperatures. These distinctions can be explained by the morphological and structural differences of interfaces in the samples based on two types of Permalloy.

Second Harmonic Generation Versus Linear Magneto-Optical Response Studies of Laser-Induced Switching of Pinning Effects in Antiferromagnetic/Ferromagnetic Films

“…Typically, the exchange bias in the AFM/FM films breaks down at temperatures exceeding T N , while in nanostructured systems this coupling has been shown to disappear at temperatures much lower than T N due to size effects. The temperature at which the hysteresis loop shift vanishes is denoted as blocking temperature T B [9,10].…”

Ferromagnetic Hysteresis by Heisenberg Partition Function and Its Processing Methods in Nanoparticle Magnetization Modeling

“…As example of a core/shell system that shows magnetization reversal (strongly affected by the presence of the shell) and, in particular, by the existence of a frustrated interfacial region playing a key role in determining the low temperature irreversibility, the finite coercitivity slightly above the Curie temperature of the phase and the horizontal displacement of the FC-hysteresis loop, which is attributed to the presence of a large fraction of surface spins [24]. In [25] The magnetization reversal sequence of the two ferromagnetic layers depends on the composition of a Permalloy. The magnetic features are explained in terms of morphological differences of the ferromagnet/antiferromagnet interfaces.…”