Physical Properties of Rare Earth-Cobalt Magnet Materials

To further define the various types of time dependences noted previously, attempts were made to return a sample to its original state. Because of the failure of these, a series of samples with nearly identical properties is being investigated. Some preliminary results are given. High temperature X-ray measurements were made of prism plane reflections. These yielded thermal expansion values in the basal plane showing no anomaly at the Curie Temperature. The widths of the X-ray lines were a function of temperature and also of previous heat treatments. The width variations are reported in some detail and attributed both to bulk and surface effects. The temperature factor was measured and can be interpreted through a Debye temperature of 281. See also report dated Feb 1972, AD742206.