Antiferromagnetic structure of thin Cr(1Â 1Â 0) films in large magnetic fields

Using unpolarized neutron diffraction the magnetic structure of 30 nm thick Cr(1 1 0) films of a V/Cr multilayer was investigated in a horizontal field of 2.6 T and a vertical field of 7.5 T at a temperature of 270 and 2 K. The horizontal field was applied parallel to the [0 1 0] and [1 0 0] direction, whereas the vertical field was applied along the [11¯0] direction. In bulk chromium, a field of 2 T parallel to the Cr polarization leads to a rotation of the polarization perpendicular to the applied field. In contrast, our experiments on thin Cr(1 1 0) films show no change of the magnetic structure in a magnetic field up to 7.5 T. A comparison of these measurements to earlier experiments on Fe/Cr(110) multilayers where the Cr polarization could be rotated easily by rotating the Fe magnetization proves the huge exchange coupling present at the Fe/Cr interface.