Magnetic properties of lithium-based spinels Li(Ni Co2−)O4

Abstract We report on the magnetic properties of the solid solution Li(Ni x Co 2− x )O 4 (0≤ x ≤1.0). LiCo 2 O 4 behaves as an antiferromagnet ( T N ∼ 35 K). The nickel substitution affects the antiferromagnetic interactions, first lowering T N (22 and 25 K, at x =0.25 and 0.50, respectively) and then increasing it up to 38 K ( x =0.75 and 1.0). A dramatic change with x (Ni) is observed for Θ, from −225 K (at x =0) up to very large positive values (+200 K or more). This is interpreted as a canted AF structure with large ferromagnetic components.