Low field magnetism and cationic distribution in quasi-stoichiometric Li1−xNi1+xO2

The low field magnetic susceptibility and X-band ESR spectra of quasi-stoichiometric Li1−xNi1+xO2 samples have been measured. The anomaly around 240 K, observed in Li0.98Ni1.02O2 under a 1 mT field, disappears under the conventional magnetic fields used in ESR or susceptibility measurements. We comment on the distribution of extra Ni ions in the lithium planes depending on the synthesis conditions. The departure of x from the exact stoichiometry determined by Rietveld refinements is not the single parameter which determines the magnetic and therefore the electrochemical properties of Li1−xNi1+xO2 samples.