Neutron diffraction on LPSO structure in Mg-Zn-Y alloys

Gong, W.; Aizawa, Kazuya  ; Harjo, S.   ; Abe, Jun; Iwahashi, Takaaki; Kamiyama, Takashi*

Crystal structure, phase fraction, and texture of LPSO (Long period stacking ordered structure) phase in ternary Mg-Zn-Y alloys have been investigated by analysis on TOF(Time Of Flight) neutron diffraction profiles using the Rietveld method. A directionally-solidified crystal MgZnY alloy made by the Bridgman technique, which consists of a single 18R LPSO phase, shows a very strong texture of (10-10) parallel to growth direction. It has been shown that the LPSO phase in the alloys is 18R-type structure in rhombohedral space group P3212 with a = 11.1823 angstrom; and c = 47.0351 angstrom.