Magnetocaloric effect and critical properties in La0.85Li0.15MnO3

The manganite La0.85Li0.15MnO3 (LLMO) was synthesized by standard ceramic preparation routes, its magnetocaloric effect and critical phenomenon have been studied by measurements of dc-magnetization. The sample is of single phase with a rhombohedral structure confirmed by the X-ray diffraction refinement. M-T data reveal that the LLMO shows a second-order magnetic transition with a T-C of 235K. Maximum values of magnetic entropy change (- S-M(max)= 5.32J K-1 Kg(-1)) and relative cooling power (RCP=320.3J kg(-1)) have been observed when the magnetic field change is up to 5T. The LLMO compound with excellent magnetocaloric effect is expected to have effective applications in sub-room temperature range. In addition, the critical behavior around its T-C is thoroughly analyzed using the field dependence of the magnetic entropy change. The determined values of critical exponents (=0.507, =1.045, and =2.982) are fairly close to the theoretical values of the mean field model (=0.5, =1.0, and =3.0), indicating the presence of long-range ferromagnetic ordering in this system. The validity of the obtained exponents is confirmed by the scaling theory.