A process of fabricating a monolithic working component for magnetic heat exchange is disclosed. The process includes mixing two or more portions comprising amounts of La, Fe, Si and at least one of T and R suitable to produce a La1-aRa(Fe1-x-yTySix)13Hz phase, wherein T is at least one element from the group consisting of Mn, Co, Ni and Cr and R is at least one element from the group consisting of Ce, Nd, Y and Pr. The amount of T, R, and Si is selected for each of the two or more portions to provide the two or more portions with differing Curie temperatures and, preferably, a density, d, within a range of ±5% of an average density, dav, of a total number of portions. The process includes heat treating a single monolithic green body formed from two or more precursor powder mixtures to produce a single monolithic working component.