Critical behavior of the electron-doped manganite La0.9Te0.1MnO3

The critical properties of electron-doped manganite La0.9Te0.1MnO3 were investigated based on the data of static magnetization measurements around Curie temperature T-C. The magnetic data analyzed in the critical region using the Kouvel-Fisher method yield the critical exponents of beta=0.201 +/- 0.003 with T-C=239.37 +/- 0.01 K (from the temperature dependence of spontaneous magnetization below T-C) and gamma=1.27 +/- 0.04 with T-C=239.71 +/- 0.01 K (from the temperature dependence of inverse initial susceptibility above T-C). The critical magnetization isotherm M(T-C,H) gives delta=7.14 +/- 0.04. The critical exponents found in this study obey the Widom scaling relation delta=1+gamma/beta, implying that the obtained values of beta and gamma are reliable. The values of the critical exponents for La0.9Te0.1MnO3 are different from those predicted by various theoretical models, e.g., three-dimensional (3D) Heisenberg model, mean-field model, and 3D Ising model, and even from those of hole-doped manganites. The beta value close to that predicted by a tricritical mean-field model and the poor scaling toward low fields suggest that the present composition might be close to a tricritical point in the La1-xTexMnO3 phase diagram.