It is the result of a systemic study about uniform hematite nanopallets with length of about 100 nm, width of about 30 nm, and thickness of less than 10 nm. The sample has superparamagnetic (SPM) properties above the blocking temperature of ~16 K. The temperature dependence of magnetization was well fitted by Bloch T3/2 law considering the dipolar interaction of the particles. The field dependence of magnetization was fitted with revised Langevin equation. The magnetization of the weak ferromagnetic (WF) canted spins contributes to the linear portion in the high field region; the surface uncompensated spins and the parasitic ferromagnetic moments due to the canted spins both contribute to the particle moments and the superparamagnetic behavior.
Keywordsα-Fe2O3 nanopallets Magnetic property Superparamagnetic behavior Canted spins
This study was financially supported by the National Natural Science Foundation of China (Nos. 11674023, 51371015, 51331002, and 51501004) and Beijing Municipal Science and Technology Project (No. Z17111000220000).
- Néel L. Théorie du traînage magnétique des ferromagnétiques en grains fins avec application aux terres cuites. Ann Geophys. 1949;5(2):99.Google Scholar
- Néel L. Low-Temperature Physics. In: DeWitt C, Dreyfus B, DeGennes PG, editors. London: Gordon and Breach. 1962. 411.Google Scholar