Exchange interactions and the nature of magnetic ordering in Zn0.6Mn2.4O4 particles

Abstract Reported here is the nature of magnetism of polycrystalline Zn0.6Mn2.4O4 (particle size ∼ 125 nm) with non-magnetic Zn2+ ions occuping the tetrahedral sites as revealed by Rietveld refinement of the structural parameters. Analysis of magnetization vs.temperature (4 K–350 K) data showed long-range ferrimagnetic order below TC = 36 K and its analysis for T > TC using the Lotgering model modified by Srinivasan and Seehra (Phys. Rev. B 28, 1, 1983) yielded the exchange constants JBB = 13.4 K, JAB = 5.0 K and JAA = 3.8 K, which are weaker by about 30–50% than those reported in Mn3O4. The other effect of magnetic dilution is the observation of spin-glass state below TSG = 5.8 K characterized by its H2/3 decrease with increase in H. Thus Zn0.6Mn2.4O4 is a ferrimagnet with triangular Yafet-Kittel arrangement of spins having a reentrant spin-glass state with TSG