Abstract
The magnetic properties of γ-Fe 2O 3 nanoclusters grown within the microdomains of optically transparent block copolymer films were investigated. SQUID magnetometry and 57Fe Mössbauer spectroscopy were employed with characteristic measurement times of 100 s and 10 −8 s, respectively. The observed magnetism of the ca. 5 nm diameter particles was dominated by quantum-size effects, collective magnetic excitations, and superparamagnetic relaxation processes associated with the sub-magnetic domain γ-Fe 2O 3 nanoclusters. The combination of these two techniques allowed determination of the values of the magnetic anisotropy constant ( K = 1.58 × 10 5J/m 3) and the pre-exponential factor ( τ 0 = 4.2 × 10 −12s) which determine the magnetic behavior of the nanocomposites. At low temperatures, the nanocomposite films exhibited hysteresis with the saturated coercivity, H c 0, equal to 530 Oe.
Sign-in/Register to access full text options 
Free) 
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
