Samarium Cobalt (SmCo) is the other Rare Earth magnet!
SmCo is the alternative to Neodymium magnets when a more stable
output over a much wider temperature range is required.
The SmCo magnets can be used from temperatures nearly as low as
absolute zero (-273°C) up to +350°C. Although Neodymium magnets
provide stronger fields at room temperature, SmCo starts to
outperform at temperatures above +150°C.
With superior temperature coefficients than Neodymium, magnetic
output from SmCo varies less over a change in temperature, making
it an ideal choice for temperature sensitive applications such as
sensors and loudspeakers where stability of the field during
operation is important.
SmCo also has a very good intrinsic coercivity allowing it to be
used in applications where high external demagnetising forces (and
high temperatures) may be present, such as the starting of an
SmCo has very little free iron in its structure meaning it offers
excellent corrosion resistance to water. It very rarely requires
protective coating (e.g. a nickel coating to allow soldering to a
printed circuit board). Because of its performance characteristics
SmCo is often used instead of Neodymium in mission critical
applications such as aerospace and military applications.
SmCo is a brittle material and could break, chip, snap or possibly
even shatter if mishandled. Care should be taken when assembling
with the SmCo (e.g. wear safety glasses).
Standard manufacturing tolerance is +/- 0.1mm on all dimensions.
Samarium Cobalt Magnet Features
Samarium Cobalt (SmCo) disc magnets are powerful magnets rare earth
magnets composed of samarium and cobalt. They are commonly used in
high performance motors, magnetic couplings and magnetic
separators. These are brittle magnets and are prone to cracking and
chipping. Samarium magnets can be used for high temperature
applications where neodymium will not work.
Samarium cobalt magnets are hard and brittle and may chip or break
They have high magnetic properties
Samarium cobalt magnets offer good thermal stability
Samarium cobalt magnets are resistant to corrosion
Samarium cobalt magnets resistant to demagnetization
A Samarium Cobalt magnet can withstand higher temperatures than a
Neodymium magnet. The maximum operating temperatures for Samarium
Cobalt magnets are between 250 and 550 °C; Curie temperatures range
from 700 to 800 °C. Additionally, a Samarium Cobalt magnet is less
subject to corrosion than a Neodymium magnet, and usually does not
require coating or plating.
Several factors must be considered to assure the effective
performance of the magnet, the adhesive and the resulting bond.
These include the chemical and physical properties of the magnets
and the surfaces to which they are affixed. Detailed coverage of
all these factors, along with some adhesives to try, is covered in
white paper Gluing Magnets.