Abstract
High- T C scanning SQUID magnetometer is applied for measuring the magnetization relaxation of the ensembles of spherical colloidal Fe 3O 4 nanoparticles dispersed in the rigid polymer matrix preventing nanoparticles from agglomeration. According to the transmission electron microscopy data, the size distribution of nanoparticles is well described by the Gaussian profile with the mean size and the dispersion of about 7.5 and 2.3 nm, respectively. High sensitivity of SQUID magnetometer allows us to study samples at low contents of the magnetic component (0.1–1.0 vol%) magnetized in low magnetic field (∼10 –4 T) produced by a low-inductance coil with short switching time (12 μs). A low content of the magnetic component provides the absence of interparticle dipolar interactions, thus simplifying significantly the theoretical description of the magnetization relaxation process. The measured magnetization relaxation curves are found to be in reasonable agreement with the numerical simulation data.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
