Magnetic phase diagram of Li[MgxMn2-x]O4 (0⩽x⩽12) spinel

The magnetic nature of the Li[MgxMn2-x]O4 spinel with x=0,18,14,38, and 12 was studied by susceptibility and μ+SR measurements. As x increases from 0, TN (= 61 K) rapidly drops down to 29 K (=TC) for the x=18 sample, and then decreases slowly with further increasing x. The sample with x=12, in which Mg2+ and Mn4+ ions order to form a 1:3 superlattice, exhibits a sharp ferromagnetic (FM) hysteresis below 15 K. The analysis of the ZF-spectrum implies the possibility that the FM order is incommensurate to the lattice. For the samples with 0