MIT Researchers Make Spintronics Breakthrough


Staff member
Mar 3, 2018
As silicon microchip manufacturing becomes more difficult, and more expensive, manufacturers are increasingly looking for alternative methods the chip industry needs to sustain its growth. One promising area is the field of spintronics, which exploits an electron's spin in addition to its charge. Theoretically, spintronics devices don't need power to retain their magnetic properties, and switching states should generate less heat. But past efforts to produce spintronics devices using ions ran into a practicality problem: the devices degraded after just a few repetitions. Researchers at MIT and at Brookhaven National Laboratory claim to have made a breathrough on this front. They discovered that hydrogen ions are small enough to "enter and exit from the crystalline structure of the spintronic device, changing its magnetic orientation each time, without damaging the material." The researchers say lab-based prototypes are less than a few years off, while something as complex as a working memory cell might take longer.

The discovery came about, in part, through serendipity. While experimenting with layered magnetic materials in search of ways of changing their magnetic behavior, Tan found that the results of his experiments varied greatly from day to day for reasons that were not apparent. Eventually, by examining all the conditions during the different tests, he realized that the key difference was the humidity in the air: The experiment worked better on humid days compared to dry ones. The reason, he eventually realized, was that water molecules from the air were being split up into oxygen and hydrogen on the charged surface of the material, and while the oxygen escaped to the air, the hydrogen became ionized and was penetrating into the magnetic device - and changing its magnetism. The device the team has produced consists of a sandwich of several thin layers, including a layer of cobalt where the magnetic changes take place, sandwiched between layers of a metal such as palladium or platinum, and with an overlay of gadolinium oxide, and then a gold layer to connect to the driving electrical voltage. The magnetism gets switched with just a brief application of voltage and then stays put. Reversing it requires no power at all, just short-circuiting the device to connect its two sides electrically, whereas a conventional memory chip requires constant power to maintain its state. "Since you're just applying a pulse, the power consumption can go way down," Beach says.
I guess I'm surprised this kind of thing isn't tested in a vacuum or something first.

Another break through the likes of revolutionary battery technologies?
"The discovery came about, in part, through serendipity."

The big ones often are! If they can scale this up (always the big "if") this is indeed huge.
This serendipitous discovery has a parallel in the nuclear fission saga: Fermi missed discovering fission because his labs in Italy were made of Marble.

The guys that discovered Fission used wood tables, and got different results, and discovered that hydrogen moderated neutrons to a lower speed, where they were more effective.

Then they tried paraffin, and now we have nuclear reactors.

(You don't need moderators for bombs; that's a different story.)