OBSERVATION OF X-RAY MAGNETIC KERR ROTATION AT GD L ABSORPTION EDGES

The first observation of the rotation of the major axis on the scattered X-ray at magnetic resonance has been performed. This rotatory power named '' X-ray Magnetic Kerr Effect '' is applicable to the investigation of spin polarization of unoccupied states. The rotation has been measured with 1eV increment between 6eV below the Gd L3 absorption edge and 6eV above the Gd L3 absorption edge. The maximum rotation is about minus 2 degrees observed at about 4eV below the edge. The peak width is about 2eV. This spectrum correspond to the 4f-state. The magnitude of the rotation between 3eV below the edge and 5eV above the edge is about 1 degree. The sign of the rotation change from plus to minus at the vicinity of the edge. This spectrum correspond to the 5d-band structure. These features agree fairly well with the theoretical prediction.