The structural and magnetic properties of MSr 2Y 1.5Ce 0.5O z (M-1222) compounds, where M = Fe and Co, were investigated. The solid-state reaction method was used to synthesis the compounds. The room temperature neutron powder diffraction (NPD) patterns for the two compounds were analyzed. The Mössbauer spectroscopy was also used in the study. For Fe-1222 compound, it was found that nearly half the Fe remained at the M site, while the other half went to the Cu site in the CuO 2 planes. It was observed that nearly 84% of Co for the Co-1222 compound remained at M site, while the rest occupied the Cu site in the CuO 2 planes.