Stripe order and spin dynamics in nickelates

We report zero field muSR experiments on the lanthanum nickelate La2-xSrxNiO4+delta system with strontium doping level x between 0 and 0.6. In a single crystal with x = 0 33 the internal field distribution shows two separated signals reflecting the antiferromagnetic domains and the non magnetic antiphase domain walls in the spin and charge ordered state below 190 K. Below 70 K a broadening of the low field line is observed. A similar behavior is observed in polycrystalline samples with 0.2 less than or equal to x less than or equal to 0.5.