Size control on the magnetism of La_0.7Sr_0.3MnO₃

Polycrystalline La_0.7Sr_0.3MnO₃ samples was subjected to high-energy planetary ball milling in order to reduce the average particle size and to study the influence of the reduced particle size on the magnetism. With increasing milling time (0–48 h), the average particle size reduces from bulk to about 20 nm. Magnetization measurements show that there is marginal change in the ferromagnetic ordering temperature; however, there is drastic reduction observed in the magnetic moment. This observation is corroborated from the neutron diffraction experiments too. The reduction in particle size also affects the magnetic anisotropy of the system and is found to decrease with decreasing particle size. Further, as the particle size is reduced, evolution of Griffith phase has been observed in the system.