Magnetic behaviour of the rare earth binary R-Fe alloys

Thermomagnetic analysis and H/sub c/ measurements in rare-earth-rich alloys of the systems Fe-Ce, Fe-Pr, and FeNd indicate the presence of two different hard magnetic phases. These phases can be metastable, and their magnetic properties are strongly affected by heat treatments at 600 degrees C. One of them is encountered preferentially in the as-cast alloys; the other appears after 600 degrees C heat treatments of two hours or more. For the Fe-Pr system the first phase has T/sub c/=222 degrees C, and the alloys in which it is detected present H/sub c/'s around 4.0 kOe. The second phase has T/sub c/=236 degrees C, and the alloys containing it present lower H/sub c/'s whose value is dependent on the duration of the heat treatments.<>