Identification of Ferromagnetic Phases

In Table V there are presented specific magnetizations and Curie points for a limited number of ferromagnetic substances of interest in 

There will now be presented some examples of the use of these data for the identification of catalyst components. It will be clear that the method is by no means limited to substances of interest in catalysis but could have useful application in mineralogy, ceramics, metallurgy, and related fields. 

This particular application is not very new (Hilpert and Dieckmann, 45). Cementite and metallic iron were identified in 1915 in an iron oxide 

Curve II shows the same sample after having been heated to 800° in a stream of nitrogen. The Curie point is no less well defined, but has fallen to about 205° which is near the Curie point for cementite. The Hagg carbide has clearly undergone a reaction owing to its instability at high temperatures. 

It must be remembered that chemical reactions in the solid state may take place while the thermomagnetic curves are being obtained This is 

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