Spin and orbital magnetism in free nanoparticles: Size, composition, and temperature effects Chapter uri icon

abstract

  • Recent progress in the quantum theory of the magnetic properties of transition-metal clusters and nanoparticles is reviewed. After a brief overview of representative experimental observations, we develop the main theoretical background required for describing itinerant-electron magnetism in nanostructures. Several complementary approaches are introduced, including density-functional theory, self-consistent tight-binding theory, and functional-integral spin-fluctuation theory. The main body of the chapter is devoted to the properties of free clusters and nanoparticles composed of transition metals and their alloys. A wide variety of remarkable effects are discussed: the size dependence of spin and orbital magnetism, the role of chemical order in magnetic nanoalloys, the structural dependence of the magnetic anisotropy energy (MAE), the possibilities of tailoring the MAE by varying the composition, and the temperature dependence of the average magnetization and spin correlations. The analysis of the results reveals the role of the local environment of the atoms; the interplay between structure, composition, and magnetic order; and the importance of electron correlations and spin fluctuations. The chapter is closed with an outlook on some challenging future research directions. © 2014 Gustavo M. Pastor.

publication date

  • 2014-01-01