Magnetic resonance in FeNi/Bi/FeNi films

The magnetic resonance in FeNi/Bi/FeNi trilayer films with nonmagnetic semimetal spacer has been experimentally studied. It is found that the microwave absorption spectrum of samples has a complicated shape dependent on the nonmagnetic spacer thickness. In the interval of Bi layer thicknesses within 3–15 nm, the interlayer coupling has an antiferromagnetic character.