Charge density analysis from complementary high energy synchrotron X-ray and electron diffraction data

Abstract To accurately measure the low order structure factors of α-Al 2 O 3 , two-dimensional convergent beam electron diffraction (CBED) data from parallel-sided platelets at various accelerating voltages, thickness and orientations have been matched using the Bloch-wave method. Middle and high angle extinction-free data has been obtained by the extrapolation of multi-wavelength synchrotron X-ray measurements to zero wavelength. The combination of high-energy synchrotron X-ray diffraction and CBED allows the extinction-free absolute-scale measurements and improves the reliability of the electron charge density maps in α-Al 2 O 3 .