Tuning magnetic and magnetocaloric properties of Pr0.6Sr0.4MnO3 through size modifications

Particle size as an effective tool for controlling the magnetic and magnetocaloric properties of Pr0.6Sr0.4MnO3 samples has been studied. In the present work, a direct influence of particle size on the magnitude of magnetization and magnetic transition temperature, T-C,T- can be seen. The T-C drops from 309 to 242 K, while the saturation magnetization (M-S) decreases from 3.6 to 0.5 mu(B)/f.u. as the particle changes from 120 to 9 nm. Concurrently, coercivity (H-C) exhibits a drastic rise emphasizing the enhanced surface disorder in the nanoparticles. Another interesting observation is in the magnetic entropy change, Delta S, which though decreases in magnitude from 5.51 to 3.90 J/Kg-K as particle size decreases from 120 to 30 nm, but the temperature range of Delta S (i.e., relative cooling power, RCP) increases from 184.33 to 228.85 J/Kg. Such interplay between magnitude and wider temperature range of Delta S, which can be fine-tuned by particle size, provides an interesting tool for using surface spin disorder, as a control mechanism in modifying physical properties.