…it up. It took a long time to find a clamp around here that wasn't made out of iron. And it will then go over its Curie point and become non-magnetic. So if I put it on the glass plate there, if I've heated it enough and not my hand, I will hope…

…us a curve when we solve it graphically or otherwise, which gives the magnetization as to the maximum as the temperature over the Curie temperature, which is something that went down theoretically so. We had a graph of it. I'll show you in a minute. In…

…when they're almost all up and only a few are down, it's easy. And at high temperatures, when you're way above the Curie point, when they're almost all random, it's easy. It's always easy to go from some simple idealized situation a little bit off.…

…out, Felix Block. It's understood physically that it should deviate here for these statistical reasons, but the exact behavior near the Curie point has never been thoroughly figured out. That's an interesting problem to work out someday if you want a problem…

…interaction of the spins, and we have here the internal energy of the system. If we take the case of spontaneous magnetization below the Curie point so that H is equal to zero, then by putting H equals zero in here and noticing that the tanh of H of…

…I'll let you try to prove that. I planned a demonstration of that fact that this goes as a square root of the Curie temperature minus the temperature, and that this goes linearly with the temperature difference. But I think I have so many things to say…

…with a little funny thing, falls like this, and continues. And this is due to the magnetism. And this occurs at the Curie point. So without any magnetic measurements at all, we could have discovered something was going on inside of iron or nickel by…

…stable only above 900 degrees centigrade, I believe. It's a different, but of course, at that temperature, it's already past the Curie point. However, by mixing with the alloying with the iron, chromium, and nickel, I believe it's 18% chromium and 8%…

…them up, they try to jiggle away, but when you get to a certain temperature, which is the corresponds to the Curie temperature for ferromagnetism, beyond that, they suddenly become random or more random. And there is a sudden transition under these…

…has defied complete analysis for years. Everything has been analyzed pretty carefully as long as you're not too close to the Curie point, but the study of the sudden transition of the Curie point has never been finished. Finally, although it didn't apply…

…pretty carefully as long as you're not too close to the Curie point, but the study of the sudden transition of the Curie point has never been finished. Finally, although it didn't apply to this lecture, the paramagnetic and nuclear resonances that we have…

…course, by writing it as T curie. over T. That's a handy little thing to do. Now, if T is greater than the Curie temperature, then we have no magnetic moment. The temperature is so high that in spite of the interaction between the moments, the…

…line marked quantum theory is the curve that we obtain. That is, when the temperature is very low, theta is the Curie temperature on this graph, the magnetization is even 100% of saturation. When the temperature rises, then the magnetization falls. The…

…magnetic moment inside and that that curve told you what the magnetic moment was as a function of temperature. Since the Curie temperature is so high, our room temperature is so low, it's almost saturated anyway. Why then isn't everything a magnet? What's…