Correlation between interfacial defects and ferromagnetism of BaTiO3 nanocrystals studied by positron annihilation

► The above paper reported a detailed study of the structure and magnetic properties of pure BaTiO3 nanocrystals. ► We confirmed that the ferromagnetism in pure BaTiO3 is related with interfacial defects. ► The results are important for the understanding of the origin of ferromagnetism in pure BaTiO3 nanoparticles.