Magnetic properties of the noble metal nanoparticles protected by polymer

Platinum metal nanoparticles having diameter ranging from 2.3 to 3.8 nm with quite narrow diameter distribution have been synthesized by chemical reaction method, and their diameter dependences of the magnetizations were measured. Pt nanoparticles having the diameter below 3.8 nm exhibited superparamagnetic behavior in the magnetization process and enhanced magnetization was observed compared to the paramagnetic moments in the bulk state. With decreasing the diameter, the magnetic moment increases and reaches 5.0mu(B)/Pt particle at 2.3 nm. (C) 2003 Elsevier Science B.V. All rights reserved.