Magnetic Enhancement in Nanoscale CoRh Particles

The influence of size reduction on the magnetism of CoRh has been studied on a system of isolated nanometric spherical bimetallic ultrafine particles embedded in a polymer matrix. Pulsed fields up to 30 T were used in order to approach the magnetic saturation ( $M_S$). Particles with a mean diameter of 1.65 $(\pm 0.1)\mathrm{nm}$ display a value of $2.38{\mu }_B$ per CoRh unit strongly enhanced compared to values calculated or measured on a bulk alloy. These results were interpreted as the first evidence of the cooperative role of both alloying and size reduction to the enhancement of $M_S$ in this system associating a $3d$ FM metal with a $4d$ metal.