Aluminum clusters: Magnetic properties

Abstract

We report the first measurement of the magnetic moments of gas phase aluminum clusters ranging in size from 2 to 25 atoms. Aluminum clusters are produced by pulsed laser vaporization of an aluminum rod inside the throat of a high pressure pulsed nozzle. The highly collimated cluster beam is passed through a Stern–Gerlach magnet and the deflected beam is analyzed by spatially resolved photoionization time-of-flight mass spectrometry. Aluminum clusters less than nine atoms in size are found to have magnetic moments generally consistent with those predicted from spin and orbital moments of the ground electronic states. As expected, a general trend toward reduced magnetic moment per atom with increasing cluster size is observed.

Large-scale first principles configuration interaction calculations of optical absorption in aluminum clusters

“…9,10 Shell structure and s-p hybridization in anionic aluminum clusters were probed using photoelectron spectroscopy by Ganteför and Eberhardt, 11 and Li et al 7 Evolution of electronic structure and other properties of aluminum clusters has been studied in many reports. [7][8][9][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Structural properties of aluminum clusters were studied using density functional theory by Rao and Jena. 8 An all electron and model core potential study of various Al clusters was carried out by Martinez et al 22 Upton performed chemisorption calculations on aluminum clusters and reported that Al 6 is the smallest cluster that will absorb H 2 .…”

Global minima of AlN, AuNand PtN,N⩽ 80, clusters described by the Voter–Chen version of embedded-atom potentials

“…In these model potential studies carried out by random search, simulated annealing or genetic algorithms, Al clusters are described by an empirical many-body potential [34], two-plus-three body Murrell-Mottram potential [35,36,37], Gupta [38] or Sutton-Chen [39] potentials. Similarly, the experimental studies on Al clusters [40,41,42,43,44,45,46,47,48,49,50,51] go back to the middle of the 1980s. It is known that while the electronic factors determine cluster stability for alkali metal clusters [52], packing and surface energy effects dominate on the structure of alkaline earth elements, such as calcium and strontium [51].…”

Estudo computacional de <i>clusters </i>de alumínio, Al_n^(+,0,-) , n = 2 - 30

“…A maior parte dos estados de spin de nossos clusters estão de acordo com os resultados de deflexão de Stern-Gerlach obtidos por Cox et al 108 e com os resultados de ressonância de spin.…”

“…Desse modo, estados de elevada multiplicidade são mais estáveis, conforme comprovado experimentalmente por Cox et al 108 Para os clusters Al n (+,0,-) , n = 6 -7, suas estruturas tridimensionais favorecem a deslocalização eletrônica e suas estruturas assumem configuração de spin dubleto (clusters contendo número de átomos ímpares) ou singleto (clusters contendo número de átomos pares). Neste capítulo iremos investigarmos o caráter da ligação química dos cluster Al 13 (+,0,-) analizando a influência da carga total sobre suas propriedades físico-químicas.…”

“…Desse modo, estados de elevada multiplicidade são mais estáveis, conforme comprovado experimentalmente por Cox et al 108 O ELF forneceu a localização eletrônica por meio de basins mono e dissinápticas e também a deslocalização eletrônica por meio de basins polissinápticas.…”