Moir\'e materials are artificial crystals formed at van der Waals
heterojunctions that have emerged as a highly tunable platform to realize much
of the rich quantum physics of electrons in atomic scale solids, also providing
opportunities to discover new quantum phases of matter. Here we use finite-size
exact diagonalization methods to explore the physics of single-band itinerant
electron ferromagnetism in semiconductor moir\'e materials. We predict where
ferromagnetism is likely to occur in triangular-lattice moir\'e systems, and
where it is likely to yield the highest Curie temperatures.Comment: 15 pages, 14 figure