Co-existence of giant magnetoresistance and large magnetocaloric effect near room temperature in nanocrystalline La 0.7Te 0.3MnO 3

Abstract

Sol–gel prepared nanocrystalline La 0.7Te 0.3MnO 3 has rhombohedral crystal structure (space group R3¯C) at room temperature and orders ferromagnetically at ∼280 K ( T C ). A large magnetic entropy change of ∼12.5 J kg −1 K −1 is obtained near T C for a field change of 50 kOe. This magnetocaloric effect could be explained in terms of Landau theory. The temperature dependence of electrical resistivity shows metal–insulator transition at T C and a giant magnetoresistance of ∼52% in 50 kOe. The co-existence of giant magnetoresistance and large magnetocaloric effect near room temperature makes nanocrystalline La 0.7Te 0.3MnO 3 a promising material for magnetic refrigeration and spintronic device applications.