Atomic Resolutionγ-ray Holography Using the Mössbauer Effect

We have observed a strong (2%) angular modulation of the total backscattered conversion electron yield, measured as a function of the incidence angle of the 14.4 keV $\gamma$ rays from a ${}^{57}\mathrm{Co}$ Mössbauer source irradiating thin epitaxial ${}^{57}\mathrm{Fe}$ film grown on MgO(001). The measured 2D pattern is the first hologram of the local surrounding of the absorbing nuclei obtained due to nuclear resonant scattering of $\gamma$ rays. The real space holographic reconstruction shows distinct features corresponding to the nearest neighbor sites in the bcc $\alpha$-Fe structure.