Samarium Cobalt

An Introduction to Samarium Cobalt

Samarium Cobalt magnets are made by a sintering process and exist in two forms. The first is Sm1Co5 and this has a maximum energy product of between 18 and 22 MGOe. The second, and more common, form is Sm2Co17 and this has a maximum energy product of between 22 and 30 MGOe.

Samarium Cobalt magnets are not as strong as the Neodymium magnets (maximum energy product of between 30 and 50 MGOe) but they have three significant advantages.

Samarium Cobalt magnets can be used at temperatures up to 350 degrees C. Neodymium magnets can be used at temperatures up to 200 degrees C. The Samarium Cobalt magnets start to outperform the Neodymium magnets around 150-180 degrees C. Also, Samarium Cobalt magnets are ideal for very low temperature applications (down to a few Kelvin above Absolute Zero) and are a first choice magnet for cryogenic applications.

The flux output of the Samarium Cobalt magnets is more stable with changes in temperature than Neodymium magnets due to having better temperature coefficients (e.g. -0.030%/°C for change in Br versus -0.100%/°C for Neodymium and -0.20%/°C for change in Hci versus -0.60%/°C for Neodymium). This can be particularly useful in critical applications such as sensors (although Alnico can be a better choice for temperature stability). It also means that Samarium Cobalt can resist demagnetisation better than Neodymium in higher temperature applications such as motors.

Samarium Cobalt magnets contain less free iron than Neodymium magnets and therefore provide better corrosion resistance than Neodymium magnets. It is very rare for Samarium Cobalt magnets to require protective plating (a noteable exception is the use of nickel plating for soldering the magnets to printed circuit boards).

These characteristics therefore make Samarium Cobalt suitable for applications such as pump couplings, sensors, loudspeakers, generators and motors, high temperature applications, wide temperature range applications and for use in corrosive (e.g. water, oil) environments.

Types of Samarium Cobalt

SmCo Disc Magnets
SmCo Discs with Central Holes
SmCo Rectangular Magnets

How to buy Samarium Cobalt

Buy Samarium Cobalt