Magnetic ordering in nanocrystalline gadolinium: A neutron diffraction study

The magnetic ordering of nanocrystalline gadolinium (crystallite sizes of 21 nm and 38 nm) has been studied using neutron diffraction and compared with that of a reference (similar to 1 mu m) sample. In contrast with bulk gadolinium in which the moments order initially parallel to the c-axis and then cant by as much as 60 degrees away from the c-axis below 250 K, before rotating back towards the c-axis on further cooling, both nanocrystalline samples order with their moments canted by about 50 degrees from the c-axis, and this canting angle is largely temperature independent. DOI: 10.1103/PhysRevB.87.064408