Magnetic structure of Li1-xNi1+xO2

We study the magnetic structure of layered Li1-xNi1+xO2 and propose a new s cheme: the AF interaction between the excess Ni2+ in the Li layers and the Ni3+ ions in the Ni planes, gives rise to the formation of ferrimagnetic cl usters, which control the physics of these systems. The values of the diffe rent interactions are estimated from a mean field calculation in the high t emperature limit. For the small x samples studied here the method does not yield an accurate value of J(AF), but it is very sensitive to the intralaye r inter actions, allowing to conclude that they are ferromagnetic. The rece nt proposal of a quantum spin-orbital liquid in this system is discussed an d the comparison with Jahn-Teller distorted NaNiO2 is made.