Neutron scattering study of the charge and the magnetic ordering in La2-xSrxNiO4

We have observed the charge and the magnetic ordering in La2-xSrxNiO4(0.28≤x≤0.46) by neutron scattering. In the c-plane, holes and spins order as a two-dimensional system, where holes form stripes and they are inserted into the antiferromagnetic ordering. Along the c-axis, the two-dimensional ordering stacks. However, the coherence along the c-axis is much weaker than that in the c-plane. We discuss how two-dimensional ordering stacks and why the coherence along the c-axis becomes weak