Ferromagnetic Behavior of (Fe^sub 1-y^Zn^sub y^)^sub 2^Mo^sub 3^O^sub 8^ (0[Less-Than or Equal To]y[Less-Than or Equal To]1) Induced by Nonmagnetic Zn Substitution

We have systematically investigated the magnetic properties of (Fe1-yZny)2Mo3O8 (0≤y≤1). The ground state of the parent compound, Fe2Mo3O8(y=0), is an antiferromagnetic (AFM) insulator. The substitution of magnetic Fe2+ with nonmagnetic Zn2+ gives rise to ferromagnetic (FM) correlation. With increasing y, the FM correlation evolves and becomes the most enhanced withy = 0.5. One of the possible explanations for the origin of the FM behavior is that Zn2+ ions prefer the octahedral oxygen coordination to the tetrahedral one. In addition, the magnetizations when y = 0.125 and 0.25 show a stepwise behavior at low temperatures, implying that several magnetic phases are competing with one another.