Ex) Article Title, Author, Keywords
New Physics: Sae Mulli 2009; 58: 232-236
Published online February 28, 2009
Copyright © New Physics: Sae Mulli.
Ahmad TANVEER and Ilsu RHEE*
Department of Physics and Energy Sciences, Kyungpook National University, Daegu 702-701
A superparamagnetic transition in the contrast agent Feridex was observed in the zero-field cooling/field cooling (ZFC/FC) and hysteresis curves. Using the ZFC curve, we could accurately determine the superparamagnetic transition temperature, which is called the blocking temperature. The blocking temperature of the diluted sample is shifted to a temperature lower than that of the undiluted sample. We could observe this phenomenon with a twelve-times diluted sample. We also observed a nonzero coercivity below the blocking temperature, but the coercivity was zero above the blocking temperature.
Keywords: Superparamagnetic transition, Iron ferrite nanoparticle, Blocking temperature