We report on the magnetic properties of the solid solution Li(NixCo2−x)O4 (0≤x≤1.0). LiCo2O4 behaves as an antiferromagnet (TNter border=0 SRC=/images/glyphs/BQ1.GIF> 35K). The nickel substitution affects the antiferromagnetic interactions, first lowering TN (22 and 25K, at x