THE NONRESONANT MAGNETIC-X-RAY SCATTERING CROSS-SECTION OF MNF2 .2. HIGH-ENERGY X-RAY-DIFFRACTION AT 80 KEV

Results of high-energy non-resonant magnetic X-ray diffraction experim ents performed on the model system MnF2 at a photon energy of 80 keV a re presented, A surprisingly high peak intensity of the magnetic 300 r eflection of 13000 photons s(-1) in the three-crystal mode and 19000 p hotons s(-1) in the two-crystal mode, with a peak-to-background ratio of 230:1 and 10:1, respectively, has been achieved. At 80 keV, the pen etration depth is 7 mm. When the path length of the beam through the c rystal is varied, the effect of volume enhancement of the intensity di ffracted by magnetic reflections is demonstrated. The Q dependence of the magnetic and the charge Bragg reflections has been measured and ag rees well with theory. The measurement of the temperature dependence o f the sublattice magnetization allows a very accurate determination of the critical exponent beta = 0.333 (3) and the Neel temperature T-N = 67.713 (2) K. Finally, the multiple charge scattering is discussed, w hich is very pronounced for the magnetic reflections of MnF2.