Magnetic x-ray scattering measurements on MnF2

We report the results of a high-resolution synchrotron x-ray scattering study of the magnetic scattering from Mn${\mathrm{F}}_2$. The temperature dependence of the magnetic order parameter was obtained from the intensity of the direct magnetic scattering of x rays from the ${\mathrm{Mn}}^{2+}$ spins. The intense, highly collimated synchrotron beam allowed for a clear, extinction-free separation of the Bragg component from the diffuse scattering even very close to the Néel temperature $T_N$. The excellent magnetic scattering signal-to-noise ratio should allow for the observation of critical scattering for temperatures within 1 mK of $T_N$.