New Magnetic Semiconductor

When you think of South Dakota you generally think of Mount Rushmore and, maybe, nuclear missiles. However, [Simeon Gilbert] will make you think of semiconductors. [Simeon], a student at South Dakota State University, won first place at the annual Sigma Xi national conference because of his work on a novel magnetic semiconductor.

The material, developed in collaboration with researchers from the nano-magnetic group at the University of Nebraska-Lincoln, is a mix of cobalt, iron, chromium, and aluminum. However, some of the aluminum is replaced with silicon. Before the replacement, the material maintained its magnetic properties at temperatures up to 450F. With the silicon standing in for some of the aluminum atoms, the working temperature is nearly 1,000F.

Although many magnetic materials (like magnetite) are also semiconductors, their properties are not generally comparable to traditional semiconductors like silicon. This has led to more research on combining magnetic materials and semiconductors to produce semiconductors that also exhibit ferromagnetism.

In theory, a control device made out of magnetic semiconductor would allow switching by charge carriers (as in a traditional transistor) but also provide control of spin state and polarization. A practical “spin transistor” could allow higher storage densities and lower power for non-volatile memory. Higher temperature devices can also reduce cooling requirements which can have important size and power savings.

Too bad that just when [Dan Maloney] finally got magnets figured out, [Simeon’s] going to add a new kind of material. If you haven’t run into the idea of spin transistors before, you might enjoy the video from National Cheng Kung University, below.

27 thoughts on “New Magnetic Semiconductor

  1. Before the replacement, the material maintained its magnetic properties at temperatures up to 232C. With the silicon standing in for some of the aluminum atoms, the working temperature is nearly 538C.

    1. Thanks for converting to degrees Celsius from degrees Fictional. I wasn’t going to bother doing that myself.

      It would be nice if Hack a Day put in some effort teaching engineering skills to the public. Imperial was, and still is, fine for measuring out an arbitrary length of string and such, but it’s terrible for doing more than basic mental mathematical operations. foot pounds. Seriously.

      1. Well first, I was using the units used in the source material. Second, I got both my engineering degrees in the US, so I pretty much find that after 30 or so years of dealing with both, I can convert back and forth pretty easily (which, I might add, drives my wife crazy). A lot of industries in the US still use non-metric. And a lot of us deal with people all over the world. It isn’t very hard to get into the mode of converting from one to another if you just relax about it. That being said, I prefer Metric when all other things are equal. In this case, I was just using the units used in the original article.

        1. I think the rest of the world are all metric. Isn’t it just the USA and Libya who still officially use Imperial?

          I picked up most of the Imperial I’ll ever need, pounds and inches, just through osmosis, so I understand it. It’s just an awful system. Multiple bases, none of which are 10, and none of the units relate to each other.

          In Metric lots of related quantities can be converted to each other without multiplying. Particularly if you’re using water, where 10x10x10cm = 1 litre = 1kg of water. A cubic metre of water would weigh a metric tonne. But even for non-water things, there’s still some useful connections between quantities.

          It’d be a good statement to make, for HAD to go metric. Use Imperial when you really must, but stick to Metric as much as you can.

      2. “Thanks for converting to degrees Celsius from degrees Fictional. I wasn’t going to bother doing that myself.
        “It would be nice if Hack a Day put in some effort teaching engineering skills to the public.”

        Testing to see if HTML tags work to highlight important points in comments.
        If YOU’RE not going to put in the effort, why should someone else?

      3. Is F imperial though? It might not be SI and scientific, but the inventor was a german from gdansk (poland) who lived most of his life in the dutch republic.
        And even if you simply go by what the Brits standardized in the weights and measures act, I don’t actually see a mention of F in the description of it.

        1. We used to use F in the bad old days, people over a certain age talk of temperatures in the 90s. Takes me a second to think about it and realise that wouldn’t immediately kill me.

          What does Fahrenheit mean, anyway? “Going-ness”?

          1. It’s more driveness, at least these days, maybe originally it was more travelness or goingness. or ‘drivity’ maybe.

            Or wait: ‘tripping’
            “Not Celcius? You tripping?” Makes perfect sense! :)

      1. If you care about precision you should either keep all of your digits or calculate tolerance alongside your main calculation. Constantly rounding because of some arbitrary rule, especially in an intermediate calculation as unit conversions frequently are, ends up in error that could be otherwise avoidable.

        Admittedly, what was given, or even if they changed the LSB to 0 in this instance (though there is no benefit to doing so) would be enough information, but that will not always be the case.

  2. Jesus you guys, I go down to the comments to see if there is any more useful information someone may have contributed, but nope. It’s nothing but people complaining about using Fahrenheit. Get over it, it’s not that difficult to convert it.

    1. Using pounds, shillings, and pence (12d=1s, 20s=1l) wasn’t difficult, but it was stupid, so the British dropped it and went Metric. Try doing your accounts in base-12-and-20, you’ll be begging for someone to invent a system more suited to human mathematics.

      Imperial measurements killed a space probe, you know!

  3. MRAM takes one step closer to reality. This means in a few years time, we should be able to troll each other about imperial vs. metric units on smaller, faster, more energy efficient machines. What’s not to like. }:~)

  4. Quick! Convert -40° C to F… (D’oh!)

    Mr. Chen’s command of the English language is pitiful. I couldn’t understand a word he said. However if you want to READ about “All-electric all-semiconductor spin field effect transistors” Just open this PDF http://arxiv.org/pdf/1506.06507.pdf

    Didn’t understand a word of it. Can someone read through it and “dumb it down” for some of us (like me)? I’m amazed that TAIWAN is doing stuff that’s not just imitation of USA ingenuity, However, I have no clue what this is and why we should care about it. Where is the FOR DUMMIES… book on stuff like this for Christ’s sake? ʘ8-|)

    SOTB

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