Critical behavior in Ti-doped manganites LaMn1-xTixO3 (0.05≤x≤0.2)

The critical properties of the ferromagnetic insulating system LaMn1-xTixO3 (0.05 <= x <= 0.2) are investigated based on the static magnetization measurements around Curie temperature T-C. The values of critical exponents, derived from the magnetic data using the Kouvel-Fisher method, yield 0.359 <=beta <= 0.378, 1.24 <=gamma <= 1.29, and 4.11 <=delta <= 4.21 with a T-C of 95-173 K. The exponent values are close to those expected for three-dimensional Heisenberg ferromagnets with short-range interactions, and the magnetic transition is understood in the context of Griffiths phase, arising from the random-temperature effects. (c) 2007 American Institute of Physics.