Neodymium (Neo) vs Samarium Cobalt (SmCo)

The output power of both of these rotors are very similar. Our motor design is based on a 28 MGOe energy product magnet and the SmCo is also rated at 28 MGOe (MegaGauseOerstead). The difference comes into play as they heat up. Since the SmCo Rotors have a very high coercivity (coercieve force), they are not easily demagnetized. Thus the SmCo Rotor can tolerate about 250-350 degree F more temperature rise than a Neo magnet before they began to lose their magnetic power.

The Curie temperature of a Neo magnet is around 320 degree C and SmCo magnets is around 800 degree C. What this means is if you heat a magnet without an external magnetic field the magnet will lose all its magnetic properties at the Curie temperature.

Also the coefficient of remanence of a SmCo magnet is about ¼ of Neo (-0.03%/C vs -0.12 %/C). Remanence is an indicator of materials ability to hold magnetization (magnetic storage). The lower coefficient shows a ¼ lower loss of magnetic force due to increase in operating temperature.

Of course you cannot run the motor this high a temperature due to other components in the motor but it will make the motor output power stay flatter for a longer time.
Bob Novak