ENERGY-DEPENDENCE OF THE ATS REFLECTIONS OF IRON PYRITE, FES2, NEAR THE FE K-ABSORPTION EDGE

The ''forbidden reflection'' intensity excited due to the ATS (anisotr opy of tensor of susceptibility) in a FeS2 (pyrite) crystal was measur ed for X-ray energy near the Fe K-absorption edge from 15 eV below the edge to 65 eV above the edge. In the region above the edge, the ATS i ntensities for (001), (003) and (011) reflections showed essentially t he same energy dependence, two sharp peaks and one broad peak. But bel ow the edge, the energy spectra of the ATS intensity depend on the ref lection plane. The azimuthal angle dependence of the intensity cannot be explained by the calculation based on only the dipole transition. T herefore, the scattering is affected by quadrupole transition.