Competing magnetic interaction in Co doped La0.7Sr0.3MnO3

This study investigates the crystallographic structure and magnetic order of a polycrystalline Co-doped La_0.7Sr_0.3MnO₃ grown by the conventional standard solid-state reaction method. Neutron powder diffraction data at 5 and 300 K confirm that increasing Co dopant concentration in the lattice results in the reduction of lattice parameters and ferromagnetic exchange interaction thereby lowering ferromagnetic peaks. This indicates that an antiferromagnetic superexchange interaction between Mn and Co ions rather than the ferromagnetic double exchange interaction is responsible for the diminished ferromagnetism in the system.