Analysis of the particle-size distribution of carbonyl iron powders by microscopy with statistical processing of results

Conclusions

• 1. As the electromagnetic properties (in particular the temperature coefficient of magnetic permeability) of carbonyl iron powders vary as a function of their particle-size variability coefficient, it is desirable that the latter should be employed as a standard characteristic of CI powders and as a parameter enabling the relationship to be revealed between the electromagnetic properties of magnetic materials based on CI powders and the latter's particle-size characteristics.

• 2. The particle-size distribution of carbonyl iron powders obeys the normal probability law, and the values of particle-size variability coefficient of the main Soviet radio grades of CI powders lie in the range from 0.4 to 0.8.

• 3. The higher the particle-size variability coefficient of CI powders, the better are their electromagnetic properties (the smaller is their temperature coefficient of magnetic permeability).

• 4. The method of calculating the particle-size variability coefficient described in this article can be expected to give good results with carbonyl iron powders, which consist mainly of particles of spherical particle shape.