Large magnetocaloric effect in manganites with charge order

In this work, we report the magnetocaloric effect (\DeltaS(M)\), around the charge/orbital ordering transition in the mixed valent manganite Nd0.5Sr0. 5MnO3. The magnitude of \DeltaS(M)\ around this first-order transition is a round three times larger than that obtained around the second-order transit ion (ferromagnetic-metallic-to-paramagnetic-insulator) in the same compound . Actually, the magnetocaloric response around the charge-order transition is comparable to pure Gd, the rare earth with the highest magnetocaloric ef fect. The possibility of an easy tuning of the charge-order transition temp eratures in doped manganites opens a way of investigation materials usable in magnetic refrigerators. (C) 2001 American Institute of Physics.