Calculation of the low-spin and high-spin states of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="italic">I</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="italic">h</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Co</mml:mi></mml:mrow><mml:mrow><mml:mn>13</mml:mn></mml:mrow></mml:msub></mml:m

Miura, Kaoru; Kimura, Hitoshi; Imanaga, Syunji

doi:10.1103/physrevb.50.10335

Cited by 20 publications

(21 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For Nϭ19 atoms we have the typical double icosahedron that is also generally accepted as the global minimum structure, although fcc and hcp fragments have also been proposed. 10,8,14 For this cluster size our magnetic moment is in good agreement with that calculated by Andriotis and Menon although the cluster size is slightly different. For Nϭ23 and 26 atoms we have polyicosahedral structures, consistent with the icosahedral growth pattern; the respective magnetic moments are 23 ϭ2.15 B and 26 ϭ1.95 B , the calculation of Guevara et al for Nϭ23 is an fcc fragment, and the corresponding magnetic moment is 23 ϭ2.0 B .…”

Section: Resultssupporting

confidence: 89%

“…2 There are such factors like the symmetry of the cluster, the local coordination, and the interatomic distances that influence the magnetism in low-dimensional systems. From the theoretical point of view, small cobalt clusters have been extensively studied by several groups, [8][9][10][11][12][13][14][15][16] mainly through ab initio schemes. Most of those calculations refer to clusters of a given geometric structure where interatomic distances are either those of the bulk or those obtained after an uniform local relaxation process starting from the bulk lattice constant.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structure and magnetism of cobalt clusters

et al. 2003

View full text Add to dashboard Cite

The lowest-energy geometric structures and isomers of freestanding Co N clusters (4рNр60) and their corresponding magnetic moments are calculated using an evolutive algorithm based on a many-body Gupta potential and a self-consistent spd tight-binding method, respectively. We found an icosahedral growth pattern for the global minimum with some hcp and fcc structures for some particular sizes, whereas for the second isomer, distorted icosahedral structures are obtained in general. With the aim to study the possible coexistence of isomers within the experimental cluster beam we assumed an equilibrium distribution and calculated for each cluster size the different coexistent structures and the relative populations at room temperature. Our results show that the coexistence is present only at some particular sizes, in agreement with chemicaladsorption and photoionization experiments. Our self-consistent tight-binding calculations considering 3d, 4s, and 4p valence electrons for the magnetic properties show that the magnetic moments for the global minima and the second isomers are in general very similar except in a small region of 20ϽNϽ40 atoms where the magnetic moment of the global minimum is smaller than that of the second isomer. We compare our results for the magnetic behavior of the global minimum with theoretical calculations available in the literature as well as with experimental results.

show abstract

Section: Resultssupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Structure and magnetism of cobalt clusters

et al. 2003

View full text Add to dashboard Cite

show abstract

“…[11][12][13] Unquenched orbital momentum has been invoked as a possible contributor to the anomalously large moments, 12,13 a conjecture that has been put on firmer footing by recent theoretical studies. 10 The size range investigated in the present study ͑n =7-32͒ complements those investigated in many of the previous studies, extending to smaller sizes for which detailed computational studies [19][20][21][22][23][24] of cobalt cluster structure and magnetism have been performed. The magnetic properties of bare cobalt clusters were first investigated via the Stern-Gerlach molecular beam deflection approach by Bloomfield and co-workers 5,7 ͑Co 33-215 ͒, by Persson 15 ͑Co 9-82 ͒, and by deHeer and co-workers 4,10,16-18 ͑Co 30-700 ͒.…”

Section: Introductionmentioning

confidence: 80%

Magnetic moments of bare and benzene-capped cobalt clusters

Knickelbein¹

2006

The Journal of Chemical Physics

View full text Add to dashboard Cite

Magnetic moments of bare cobalt clusters Co(n) (n=7-32) and benzene-capped cobalt clusters Co(n)(bz)(m) have been measured at temperatures ranging from 54 to 150 K using a molecular beam deflection method. It was observed that Co(12-32) produced at temperatures greater than approximately 100 K display high-field-seeking behavior at all temperatures in the range investigated, indicating that they are superparamagnetic species. At temperatures below approximately 100 K, the field-on beam profiles of Co(7-11) and some larger clusters displayed substantial symmetric broadening, indicating that some fraction of the clusters in the beam were no longer superparamagnetic, but rather were in a blocked (locked-moment) state. In the superparamagnetic regime (T=150 K) Co(n) clusters in the n=7-32 size range were found to possess per-atom moments ranging from 1.96+/-0.04 micro(b)(Co(24)) to 2.53+/-0.04 micro(b)(Co(16)), significantly above the bulk value of 1.72 micro(b). Locked-moment isomers were found to display moments of approximately 1 micro(b) per atom. Cobalt clusters containing a layer of adsorbed benzene molecules were found to possess significantly lower moments per cobalt atom than the corresponding bare cobalt clusters.

show abstract

“…The contraction ratio ranges from 3% in Ru 13 (O h ) to 8% in Ru 4 (T d ). Such a contraction effect has been found in many metal clusters both theoretically 8,[24][25][26][27]34 and experimentally, 35 and can be considered as a reflection of cluster surface effects.…”

Section: A Ru 13mentioning

confidence: 92%

“…1 Recently, such discrepancies between theories and experiments have been eliminated partially by the finding that both 3d-and 4d-TM clusters may have more than one selfconsistent magnetic solution at their equilibrium geometries. [23][24][25][26][27] Lee and Callaway 23 studied the possible multiple magnetic solutions in V and Cr clusters with bcc structures, and found that there exist as many as four or five magnetic states in V 9 and Cr 9 clusters for some interatomic spacings. They found that the ground states of the clusters correspond to the lowest-spin solutions with magnetic moments in good agreement with the experimental ones, and that the magnetic states obtained in previous studies are just their highest-spin solutions.…”

Section: Introductionmentioning

confidence: 99%

Electronic properties and magnetism of ruthenium clusters

et al. 1996

View full text Add to dashboard Cite

The electronic properties and magnetism of Ru N clusters ͑Nϭ4, 6, 10, 13, 19, 43, and 55͒ are studied using the discrete-variational local-spin-density-functional method. The bond lengths in the clusters with Nр13 are optimized, and the cluster binding energies are found to increase monotonically with the increase of cluster size. All clusters except Ru 19 are shown to have magnetic ground states. The average magnetic moments per atom for the Ru N are found to decrease rapidly with the increase of the cluster size, although small oscillation exists. The calculated moments per atom for Ru 10 and Ru 13 clusters are in good agreement with the experimental values. Multiple magnetic solutions are explored, and double magnetic solutions are found for the icosahedral (I h ) Ru 13 cluster which is used successfully to eliminate the contradiction between the previous theory and experiment on the moment of Ru 13 cluster. The electronic structures of Ru N clusters are calculated, and indicate that all clusters are metallic in behavior. The comparison between the Ru 55 cluster and the bulk counterpart indicates that Ru 55 has shown bulklike properties in the binding energy, magnetism, valence-bandwidth, and density of states. Based on electronic-structure results, the reactivity of Ru 6 , Ru 19 , and Ru 43 clusters toward H 2 , N 2 , and CO molecules is predicted. ͓S0163-1829͑96͒10927-9͔

show abstract

Calculation of the low-spin and high-spin states ofIhCo13

Cited by 20 publications

References 18 publications

Structure and magnetism of cobalt clusters

Structure and magnetism of cobalt clusters

Magnetic moments of bare and benzene-capped cobalt clusters

Electronic properties and magnetism of ruthenium clusters

Contact Info

Product

Resources

About