Structure of amorphous Mn-Si-P-alloys

The possibility of straightforward calculation of the three partial structure factors was investigated. The composition of the specimens was Mn74Si23P3. The X-ray experiment was done using MoK(alpha)-radiation. For the neutron diffraction experiment, the instrument at the ILL, Grenoble, was used, and for the electron diffraction experiment, a 50 kV SHEED-machine with an electrostatic energy filter was employed. From the scattering intensity, the Ashcroft-Langreth total structure factors were obtained, having applied the usual correction and normalization procedures. For the electron diffraction experiment, it was possible to prepare small pieces of amorphous Mn74Si26. A premaximum, which indicates very strong chemical short range order, was seen in the Ashcroft-Langreth total structure factor for Mn74Si23P3. The possibility of the determination of the three partial structure factors by a three-beam experiment was studied. The conclusion is that a straightforward calculation of the three partial structure factors is not possible from the total structure factors measured by three different radiations. The replacement of Si by P resulted in softening of the structure. (Kato, T.)