Ferromagnetic to paramagnetic

The work on iron-nickel alloys has described shock-compression measurements of the compressibility of fee 28.5-at. % Ni Fe that show a well defined, pressure-induced, second-order ferromagnetic to paramagnetic transition. From these measurements, a complete description is obtained of the thermodynamic variables that change at the transition. The results provide a more complete description of the thermodynamic effects of the change in the magnetic interactions with pressure than has been previously available. The work demonstrates how shock compression can be used as an explicit, quantitative tool for the study of pressure sensitive magnetic interactions. 

Let us mention some examples, that is, the passivation potential at which a metal surface suddenly changes from an active to a passive state, and the activation potential at which a metal surface that is passivated resumes active dissolution. In these cases, a drastic change in the corrosion rate is observed before and after the characteristic value of electrode potential. We can see such phenomena in thermodynamic phase transitions, e.g., from solid to liquid, from ferromagnetism to paramagnetism, and vice versa.3 All these phenomena are characterized by certain values... 

CURIE-WEISS LAW. The transition from ferromagnetic to paramagnetic properties, which occurs in iron and other ferromagnetic substances at the Curie point, is accompanied by a change in the relationship of Ihe magnetic susceptibility lo the temperature. P. Curie stated in 1895 that above this point the susceptibility varies inversely as the absolute temperature. But this was found in be not generally true, and was modified in 1907 by P. Weiss to stare that the susceptibility uf a paramagnetic substance above the Curie point varies inversely as the excess of the temperature above that point. At or below the Curie point, the Curie-Weiss law does not hold. 

Figure 3.17 Heat-flux DSC trace at 10°C/min of the ferromagnetic to paramagnetic lambda transformation at 354°C in nickel (dotted line). The Curie temperature indicated by the DSC trace is 346°C (dot-dashed line).

FMR studies in various Gd-rich Gdi jT alloys with T== Mn, Fe, Co, Ni, Cu, Rh, Pd, Pt or Gd were made by Buschow et al. (1980). For several of these alloys the constant was determined and found to be positive. The broadness of the ferromagnetic-to-paramagnetic transition found in the NMR experiment was explained on the basis of a wide distribution of local magnetizations in these alloys. 

Curie temperature Temperature of transition from ferromagnetism to paramagnetism, or from a ferromagnetic phase to a paramagnetic phase. 

We define the Curie temperature Tc as the temperature where the ferromagnetic to paramagnetic transition occurs, and there is a divergence in the susceptibility ... 

Curie temperature Transition temperature of a material from ferromagnetic to paramagnetic. Galvanic corrosion Dissolution of metal driven by macroscopic differences in electrochemical potential, usually as a result of dissimilar metals in proximity. 

Curie temperature Transition temperature of a material from ferromagnetic to paramagnetic. 

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