I guess what puzzles me is how the heck did they know *where* to look? Was there any theoretical work suggesting that the Rare Earth elements might lead to strong magnets? Or were they just throwing stuff at the wall, trying random combinations?

Of course, the follow-on question is: what other marvels might lurk somewhere in the periodic table?

@Dave Higgen: probably a combination of both… YCo5 was discovered at US Air Force Materials Lab at Wright-Patterson AFB in the 1960s, with further work leading to the discovery of SmCo5 and later Sm2Co17 type compounds. The independent discovery of NdFeB-based magnet materials was announced at the Pittsburg MMM conference in 1983, by Croat et al of the General Motors Research Lab (using a rapid solidification process) and Sagawa et al from Sumitomo Special Metals (using a sintered powder method). Alloy systems based on Fe were of significant interest because of the lower costs than Co, and greater availability.

There was also important earlier work done by Koon and his team at the US Naval Research Lab, which was arguably essential to the subsequent success of the other two groups. To my knowledge there was no collaboration between any of these groups.

Interestingly there was at least one group, working in Russia, that had published work on the NdFe(B) alloy system in the late 1970s, but did not, to my knowledge, look at the magnetic properties.

NdFeB was discovered in 1984 by General Motors and Sumitomo Special Metals in a joint research effort to replace Samarium Cobalt after the cobalt shortage of 1978 in Zaire.

The US Dept of Energy’s ARPA-E program funds a number of universities, Northeastern University included, to investigate “rare-earth free” magnetic materials.

As a scientifically literate (but uneducated in this area) bystander, I’ve always wondered how the newer magnetic materials were discovered?

First Samarium cobalt, then NIB… was there any (maybe quantum-mechanical) theory behind this, or was it just accidental serendipity?

I’ve never seen any history of this… it would be very interesting to learn more!

Dave Higgen

@ Vladimir Seredin
The potential Ga supply from coal is huge. Always was. However, can you point to any producer which has produced meaningful amounts of Ga from coal ash in the last 30 years anywhere in the world?

To me gallium from coal is a typical pie-in-the-sky resource.

@Claudio Holanda: it now appears that this is a thin-film material, doubly unsuited for bulk permanent magnets.

@Eamon Keane: the paper is presently available at http://arxiv.org/ftp/arxiv/papers/1111/1111.6267.pdf – per Chuanbing Rong at Ford: “The composition is Mn2Ga~Mn3Ga, indicating 30~38wt%Ga. The coercive field is up to 2.5 T. However, the saturation magnetization (potential remanence) is only 130 emu/cc = 0.16T, compared with NdFeB’s 1.6T. Actually, all Mn-based magnets have low Ms, which is not strange.”

Alos, there appear to be clnflicting data for Ga production, even within a single paragraph of the US Geological Survey’s summary on gallium – either 106 t or 184 t depending on which sentence we look at…

@Dr. Jim Wolter: your appoint about nameplate versus actual production rates is acknowledged :-)

@Ferdy Pacheco: thanks for the link. I guess we could call that a Ga deposit, though the concentrations of Ga are not exactly high…

@ Paul Gubbens: indeed – we use rare earths for a reason!

@gobucks: thanks for the chuckle :-)

@ Mycroft Risby-Saxham: as mentioned above, I’ve seen two different numbers from the US Geological Survey’s own publication on Ga (106 t and 184 t respectively); I’m sure there are other estimates out there too.

Good piece.

However, I’m afraid your figure for annual gallium production is way out.

In 2010 alone, primary gallium production was estimated to have been north of 200 tonnes, excluding any recycling.

Have a fine New Year.

Happy Holidays to everyone!

American manganese (AMY.V) (actually a Canadian company), has a very nice project in Arizona. Should be coming online in couple of years.

Two things.

1. The first thing you hear about a new material is always the best thing you hear about it.
2. Nanoscale manufacturing is great as long as you need nanograms of material.

OK, three things.

3. Manganese may be cheap, but there are no domestic sources.

Merry Christmas to all!!!