Shift of TB towards a lower temperature. Varying the magnetite solution from 8 to 4 mg Fe/ml and further to 2 mg Fe/ml leads to a shift of the blocking temperature from TB = 170 K (triangles) to TB = 75 K (circles) and to TB = 55 K (squares). For all three solutions, the size of the particles is 8 nm.
Rumpf et al. Nanoscale Research Letters 2012 7:445 doi:10.1186/1556-276X-7-445