Bashar Issa1, 2, Ihab Obaidat1, Shahnaz Qadri2, Yousef Haik, 23
1Physics, UAE University, Al-Ain, AD, United Arab Emirates; 2CREN, UNCG, Greensboro, NC, United States; 3Mech Eng, UAE University, Al-Ain, AD, United Arab Emirates
The magnetic and NMR relaxation properties of Gd-substituted Mn-Zn ferrite nanoparticles are studied at different temperatures. Magnetization data yielded a decrease in the saturation magnetization with temperature while the average magnetic moment of the particle increased. We propose that heating the particles increased the particle volume and hence its magnetic moment, with larger expansion at the surface shell layer than at the core of the particle. Only when temperature dependent particle size and magnetization are taken into account a close agreement between T2 data and model can be obtained. This enables correct characterization of contrast agent effect on MR images.