Some embodiments include a magnetic tunnel junction which has a conductive first magnetic electrode containing magnetic recording material, a conductive second magnetic electrode spaced from the first electrode and containing magnetic reference material, and a non-magnetic insulator material between the first and second electrodes. The magnetic recording material of the first electrode includes a set having an iridium-containing region between a pair of non-iridium-containing regions. In some embodiments, the non-iridium-containing regions are cobalt-containing regions.