Effect of grain size on charge and spin correlations in Bi0.5Ca0.5MnO3 manganite nanoparticles

• Effect of grain size on charge and spin correlations in Bi0.5Ca0.5MnO3 are studied.
• The samples with GS 27, 450 and 1080 nm were synthesized by sol–gel method.
• The temperature dependent electron spin resonance (ESR) and magnetization measurements were carried out.
• The evolution of different magnetic correlations with decrease in GS are ascribed to increase in surface to volume ratio of grains.

In this work we report the electron spin resonance (ESR) and magnetization (M) studies to understand the effect of grain size (GS) on the charge ordering and spin correlations in Bi0.5Ca0.5MnO3 manganite synthesized by sol–gel method. The suppression of charge ordering (CO), long-range antiferromagnetic (AFM) state, shifting of ferromagnetic (FM)-cluster glass (CG) transition towards higher temperatures and evolution of different magnetic correlations with decrease in GS are discussed in view of the changes in surface to volume ratio of nano-grains.