Sunday, March 29, 2015

Samarium: The Audiophile Rare Earth?

Given that we common folk usually encounter it in our consumer electronic gear – especially hi-fi, does samarium represent the audiophile side of the rare earth elements? 

By: Ringo Bones 

More famously known in those ultra-small yet very powerful samarium-cobalt permanent magnets, the rare earth element samarium’s “global strategic importance” seems to be just way greater to be left to geopolitical tensions give that if Beijing blocks supplies destined to the rest of the planet, it would be us civilians – especially the audiophile community – that would be left high and dry. Given its importance in our modern way of life, it would only be proper to know a bit more about this largely obscure member of the rare earth kingdom. 

Discovered by Lecoq de Boisbaudran in 1879 and further chemically refined to be identified to be a member of the rare earth family by Carl Auer von Welsbach back in 1885, the rare earth element samarium’s contribution to human civilization would not be fully realized until almost 90 years after its discovery. The primary source of the rare earth element samarium is the mineral samarskite – which is named after a 19th Century Russian mining officer, Colonel V.E. Samarsky. 

During the American science boom of the 1960s, samarium was often experimented in laser applications. Calcium chloride crystals doped with samarium have been employed in laser devices for producing beams of light intense enough to burn metal or bounce off the moon. Its more widespread applications in the civilian consumer electronics market now includes those small but powerful samarium-cobalt magnets used in hi-fi headphone units and the small electric motors used in almost everything from disc drives in CD and DVD players and the memory drives and cooling fans in personal computers and laptops. Samarium-cobalt magnets are also extensively used in the actuators of unmanned drones. As a scientific curiosity, the isotope samarium-152 is the only alpha particle emitting radioactive element known to occur naturally among the elements lighter than bismuth. Samarium-152 has a half-life of 1-trillion years. 

No comments:

Post a Comment