Particle size effects on stripe ordering and magnetic properties in nanosized La5/3Sr1/3NiO4

The structural, magnetic and transport properties of stripe ordered La5/3Sr1/3NiO4 nanoparticles synthesized by the sol–gel method were investigated. Compared with the bulk sample, it is found that the charge order is weakened in the nanosized particles. Accompanied by the disappearance of the antiferromagnetic spin-ordered state, a ferromagnetic-like phase emerges at ∼23 K. Furthermore, the spin glass/spin reorientation transition temperature T C A for the ∼100 nm particles is ∼65 K which is ∼12 K higher than that of the bulk. This suggests that instead of the stabilization of charge order, the structural disorder may have a dramatic effect on the complex magnetic transition in the stripe phase systems.