Core-shell model for the magnetic properties of Pd nanoparticles

Control of magnetite primary particle size in aqueous dispersions of nanoclusters for high magnetic susceptibilities

“…The observed reduction in saturation magnetization with a decrease in primary particle size may be attributed to this surface layer, which becomes a larger fraction of the total particle volume. The size dependence of the saturation magnetization for magnetite nanoparticles via tailored hydrolysis reaction has also been well characterized in previous studies 27,52,60 .…”

Growth mode-dependent ferromagnetic properties of palladium nanoclusters

“…17 Due to its relatively large D( F ), Pd is a candidate as a material for realizing switching of magnetism with external controls, such as charging and strain, as the magnetism exhibited by Pd is very sensitive to the changes in atomic structure and environment. 18 Ferromagnetism in bare Pd fine particles was first reported by Tanyama et al in 1997, 19 since then others have also reported similar findings, 10,14,17,[20][21][22][23][24][25][26] see Table I for a literature survey of magnetic characterization of bare Pd nanoparticles. What exactly gives rise to the occurrence of magnetism at the nanoscale in otherwise nonmagnetic materials is still not answered; it is thought to originate from unstable surface atoms in nanosized particles and it has been proposed 10,14,19 to be associated with the top few atomic layers in (100) facets.…”

Magnetic Properties of Nanoparticles

“…This is because surface atoms of NPs experience reduced symmetry compared to atoms in the core of a NP producing unsaturated bonds on surface atoms and associated surface energy and anisotropy [1]. In heterogeneous catalysis, surface adsorption of a gaseous molecule such as H2 on a catalyst in the atomic state is usually the first step since it is energetically favorable to compensate the unsaturated bonds and lower the surface energy [2].…”

“…To increase the proportion of the surface atoms whose number density increases inversely with the size D of the NPs, highly dispersed catalysts with nanoscale dimensions are usually used in catalysis. The different electronic states of surface atoms can also affect the magnetic properties of the NPs in a similar manner providing correlation between catalysis and magnetism [1].…”

“…The electric properties of composite or nanocomposite films come in on foreground of interest, especially near the percolation threshold. The parameter which influences the electric properties of composite structures is the metal volume fraction [1] contained in dielectric material. The metal particles are completely insulated from each other at low values of metal volume fraction, near the critical value of it they form a percolation structure, and the structure embodies the metallic behaviour with dielectric inclusions above this value.…”