Why do typical magnetic metals and oxides have different Curie temperatures (TC)? For example, TC = 1404, 1043, and 631 K for Co, Fe, and Ni, respectively; and TC = 860 and 369 K for spinel ferrite Fe3O4 and perovskite manganite La0.7Sr0.3MnO3, respectively. Until now, no satisfactory explanation for this magnetic ordering puzzle has been found although Weiss proposed the molecular field assumption for magnetic ordering in 1907. In this letter, we propose an explanation for this puzzle using a Weiss electron pair model based on atomic physics theory.
