Perovskite manganates with the general formula L1-xAxMnO3 (e.g. L=La, Pr , Nd and A=Ca and Sr) have attracted significant interest as a result of their unusual transport and magnetic properties, in particular colossal magnetoresistance (CMR) behaviour. Another way of modifying the structure and hence the properties is to further substitute on the manganese site with iron and gives rise to further novel and controllable magnetic and transport properties to yield materials with the general formula L1-xAxMn1-yFexO3. It is important to obtain low temperature neutron diffraction data to fully understand the complex magnetic nature of these materials. The aim of this experiment is to do that on a series of such materials to understand some novel unexpected magnetic properties