Magnetic Enhancement in Nanoscale CoRh Particles

Abstract

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 (+/-0.1) nm display a value of 2.38 micro(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.

Modification of the charge ordering in Pr1∕2Sr1∕2MnO3 nanoparticles

“…3). This type of unsaturated magnetization even in presence of quite high magnetic field for nanoparticles has been observed in some earlier experimental studies 16,21 . Magnetization for 45 nm sample is larger than that in 30 nm for all field values at 225 K. However, at 3.3 K the situation reverses, there magnetization for 30 nm sample is larger than that for 45 nm.…”

Structural study of bimetallicCoxRh1−xnanoparticles: Size and composition effects

“…The bimetallic character of these particles has been established by different results, in particular the magnetism 3 the PVP samples. However, the way the different species organize inside a particle requires the use of elementsensitive techniques.…”

“…1,2 Combining size effects and alloying with a 3d metal, already known as an effective way to induce spin polarization in 4d metals, was recently undertaken in our group. 3 In this previous paper, we reported the synthesis and magnetic study of bimetallic Co 0.5 Rh 0.5 particles with diameters lying in the 1 -3 nm range. The synthesis process, already successfully followed for cobalt clusters, 4,5 was based on the decomposition of organometallic precursors in mild conditions of pressure and temperature in the presence of a polymer, the polyvinylpyrrolidone (PVP).…”

Application of a parallel genetic algorithm to the global optimization of medium-sized Au–Pd sub-nanometre clusters

“…There is additional complexity introduced by multi-directional bonding, unrestrained bond orders, and fluxional behaviour as a result of electron delocalization. In addition, alloying Pd with Au modifies the lattice distance between host atoms and the low dimensionality of Au could influence the spatial arrangement of Pd atoms [39,40].…”