Why is a ferromagnet above the Curie temperature a paramagnet? Considering me, it's because a paramagnet has a higher entrope and since $\frac{1}{T} = \frac{\partial S}{\partial E}$. If T increases then $\frac{\partial S}{\partial E}$ should decrease and thus ....

Another thing I thought about it is that when a magnet is at a higher temperature it has more energy and thus it can more 'fight' against an extern field. This looks to be in contrare with this statement...

I've also looked at the curie law: $m = tanh(\frac{\beta \mu}{k_b T})$. If now the temperature decreases than $\mu$ increases until it flattens out (tanh function). Is het point where m flats out, the critical point, because then all spins are aligned, and thus the paramagnet becomes a ferromagnet? If the temperature increases, $\mu$ goes to zero, and thus the spins are all random (=paramagnet?

Thanks in advance


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