Tricritical point in hole-doped manganite La0.5Ca0.4Li0.1MnO3

The critical behavior of hole-doped perovskite manganite La0.5Ca0.4Li0.1MnO3 has been investigated based on the static magnetization measurement around the second-order paramagnetic-ferromagnetic (PM-FM) transition at 250.5 K. The critical exponents beta = 0.255 +/- 0.001 and gamma = 0.987 +/- 0.006 have been obtained based on both the modified Arrott plot and the Kouvel-Fisher method. The critical isotherm analysis gives delta = 4.90 +/- 0.07. The critical exponents fulfill the Widom scaling relation delta = 1 + gamma/beta and obey the single scaling equation M(H, epsilon) = epsilon(beta) f +/-(H/epsilon(beta+gamma)), implying the reliability of the obtained exponents. Its relative cooling power (RCP) is found to be scaled with the magnetic field (H) by the law of RCP similar to H1+1/delta. The critical-exponent values deduced here approach the theoretical prediction of the tricritical mean-field model, which suggests that the present composition should be close to a tricritical point in the phase diagram of hole-doped manganite La0.5Ca0.5-xLixMnO3. Copyright (C) EPLA, 2014