M(h) data is S-shaped without any hysteresis loop that means sample is superparamagnetic?
ZFC Susceptibility shoud exhibit a broad maximum, while FC curve should be irreversible.
If you have the possibility to perform alternative susceptibility measurements, the position of the maximum would depend on the frequency (Arhenus relaxtation law's)
Superparamagnets behave as ordinary paramagnets. The only difference is much higher susceptibility, dM/dH at H=0 for superparamagets, which is proportional to magnetic moment of a 'single-domain grains' rather than of a single magnetic molecule. To distinguish superparamagnet from a very soft ferromagnet one should investigate M(H) taken at various temperatures. For superparamagnets the curves M(H/T) should coincide, even if grains have varying diameters. Typical magnetic moment in superparamagnets is of order 105 Bohr's magnetons. For more details see:
Article Superparamagnetism in a nanocrystalline Fe-based metallic glass
Article EXPERIMENTAL EVIDENCE FOR SUPERPARAMAGNETISM IN NANOCRYSTALL...
maybe with
Article Langevin granulometry of the particle size distribution
Thank you sir for your answer.
Sir, I want to prove that the sample is SPM and nothing else. What types of measurements and results I will need for this? I have only M(T) - M(H) data of sample.
Oleg Petracic sir.
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