Neutron Diffraction on LPSO Structure in Mg–Zn–Y Alloys

Crystal structure, phase fraction and texture of long period stacking ordered structure (LPSO) phase in ternary Mg–Zn–Y alloys have been investigated by analysis on time-of-flight (TOF) neutron diffraction profiles using the Rietveld method. It has been shown that the LPSO phase in the alloys is 18R-type structure of space group P3212 with a = 1.1182(0) nm and c = 4.7032(5) nm. The LPSO phase shows very strong [101̄0] texture parallel to the growth direction in a directionally-solidified crystal alloy.