Stripe order in highly doped La2-xSrxNiO4

Stripe order in La2-xSrxNiO4 with 0.289less than or similar toxless than or similar to1/2 was studied with the neutron-diffraction technique. The stripe order of holes and spins was observed at low temperatures in all samples. The incommensurability E of the stripe order is approximately linear with the hole concentration n(h) up to x = 1/2. We found that the stripe is most stable at n(h) = 1/3 with epsilon = 1/3 from the analyses of the onset temperatures of the charge and spin orderings and the n(h) dependence of the correlation length of the stripe order. The stability of an 8 = 1/3 stripe induces a systematic deviation of E from the epsilon = n(h) law for samples with n(h) not equal 1/3. This deviation affects the stripe order on both sides of the hole concentration with n(h)<1/3 as well as n(h)>1/3.