THE ORIGIN OF NONLINEAR LN(T) BEHAVIOR IN THE TIME-DEPENDENCE OF MAGNETIZATION

Non-linear behaviour in the ln(t) law of time dependence of magnetisation is found to be governed by the distribution function of the energy barriers f(DELTA-E) within the system. The variation of the magnetisation with In(t) is predicted to be concave downwards when f(DELTA(t)) is increasing with time, and concave upwards when f(DELTA-E(t)) is decreasing with time. A linear ln(t) law is only the case when f(DELTA-E(t)) is approximately constant with time.