Magnetic properties and specific heat of LaMn1-xTixO3+delta (0 < x <= 0.2)

We present a magnetic study of the insulating perovskite LaMn1-xTixO3+delta (0<xless than or equal to0.2) including measurements of magnetization, susceptibility, and magnetic relaxation. The Curie temperature was found to decrease with increasing content of Ti. Two distinct magnetic transitions, irreversibility, non-exponential relaxation and aging effects confirm a reentrant spin-glass state for x = 0.2. The time decay of the magnetization has an algebraic functional form for times up to 2 h. The specific heat also displays characteristic features of a spin-glass system by a linear low-temperature dependence and a broadened peak near the temperature of the reentrant transition. (C) 2002 Elsevier Science B.V. All rights reserved.