CORRELATION BETWEEN PEAK AND MEDIAN BLOCKING TEMPERATURES BY MAGNETIZATION MEASUREMENT ON ISOLATED FERROMAGNETIC AND ANTIFERROMAGNETIC PARTICLE-SYSTEMS

The influence of the particle size distribution on the ratio of the pe ak temperature, T-peak, to the blocking temperature, T-Bm, in zero fie ld cooled (ZFC) magnetization curves has studied for both ferromagneti c and antiferromagnetic particle systems. In both systems the ratio be ta=T-peak/T-Bm does not depend on the median particle volume. However, T-Bm can be considerably different from T-peak in both systems. These results show that the ZFC measurements can be used to determine T-Bm values only if the particle size distribution of the system is known. Otherwise, the estimated T-Bm values will have a large uncertainty, es pecially in systems with a broad particle size distribution. (C) 1997 Acta Metallurgica Inc.