Evaporation from small particles

Klots, Cornelius E.

doi:10.1021/j100332a005

Cited by 288 publications

(156 citation statements)

References 5 publications

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“…Since G m varies only slowly with time, the decay rate is nearly proportional to t −1 [6,11,13,33]. It is interesting that the width of the region contributing effectively to the decay rate is quite narrow, 2σ/T m 2G −1 m < 10%, narrower by more than a factor of two than the width of a canonical distribution.…”

Section: Depletion and Coolingmentioning

confidence: 98%

Radiative cooling of fullerene anions in a storage ring

Andersen

Gottrup

Hansen

et al. 2001

The European Physical Journal D

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Abstract. Thermionic emission from hot fullerene anions, C − N , has been measured in an electrostatic storage ring for even N values from 36 to 96. The decay is quenched by radiative cooling and hence the observations give information on the intensity of thermal radiation from fullerenes. The experiments are analysed by comparison with a simulation which includes the quantisation of photon energy and the statistics of emission. Experiments with heating of the molecules with a laser beam confirm the interpretation of the observations in terms of radiative cooling and give an independent estimate of the cooling rate for C − 60 . The measured cooling rates agree in general within a factor of two with the prediction from a classical dielectric model of a thermal radiation intensity of ∼ 300 eV/s for C60 at 1 400 K, scaling approximately with the 6th power of the temperature and with the number of atoms in the molecule. PACS

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Section: Depletion and Coolingmentioning

confidence: 98%

Radiative cooling of fullerene anions in a storage ring

Andersen

Gottrup

Hansen

et al. 2001

The European Physical Journal D

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“…72 Key ingredients of this model are that the initial cluster distribution is broad, dissociation is a statistical process, and each cluster ion that is observed has undergone at least one evaporation. The small heat capacity of clusters containing less than n ≈ 10 2 units ensures that each evaporation cools the cluster significantly, thus leading to a drastic (at least a factor 10) reduction of the rate coefficient k. As a result, an ion ensemble that is interrogated at some time t after ionization will be characterized by rather well defined upper and lower limits to its (vibrational) excitation energy E n * .…”

Section: Abundance Anomalies and Adsorption Of H 2 On Graphitic Sumentioning

confidence: 99%

Adsorption of hydrogen on neutral and charged fullerene: Experiment and theory

Kaiser

Leidlmair

Bartl

et al. 2013

The Journal of Chemical Physics

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A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu The Journal of Chemical Physics 132, 154104 (2010) Helium droplets are doped with fullerenes (either C 60 or C 70 ) and hydrogen (H 2 or D 2 ) and investigated by high-resolution mass spectrometry. In addition to pure helium and hydrogen cluster ions, hydrogen-fullerene complexes are observed upon electron ionization. The composition of the main ion series is (H 2 ) n HC m + where m = 60 or 70. Another series of even-numbered ions, (H 2 ) n C m + , is slightly weaker in stark contrast to pure hydrogen cluster ions for which the even-numbered series (H 2 ) n + is barely detectable. The ion series (H 2 ) n HC m + and (H 2 ) n C m + exhibit abrupt drops in ion abundance at n = 32 for C 60 and 37 for C 70 , indicating formation of an energetically favorable commensurate phase, with each face of the fullerene ion being covered by one adsorbate molecule. However, the first solvation layer is not complete until a total of 49 H 2 are adsorbed on C 60 + ; the corresponding value for C 70 + is 51. Surprisingly, these values do not exhibit a hydrogen-deuterium isotope effect even though the isotope effect for H 2 /D 2 adsorbates on graphite exceeds 6%. We also observe doubly charged fullerene-deuterium clusters; they, too, exhibit abrupt drops in ion abundance at n = 32 and 37 for C 60 and C 70 , respectively. The findings imply that the charge is localized on the fullerene, stabilizing the system against charge separation. Density functional calculations for C 60 -hydrogen complexes with up to five hydrogen atoms provide insight into the experimental findings and the structure of the ions. The binding energy of physisorbed H 2 is 57 meV for H 2 C 60 + and (H 2 ) 2 C 60 + , and slightly above 70 meV for H 2 HC 60 + and (H 2 ) 2 HC 60 + . The lone hydrogen in the odd-numbered complexes is covalently bound atop a carbon atom but a large barrier of 1.69 eV impedes chemisorption of the H 2 molecules. Calculations for neutral and doubly charged complexes are presented as well.

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“…The order of reaction for the AsH 3 supply (1.3 for AA mode and 0.7 for AG mode) is smaller than that for the TEG supply (1.4 for AA mode and 1.9 for AG mode). From the theorem of monomolecular reactions [82] and unimolecular collision [83], Be(MeCp) 2 is less activated by the TEG supply, and thus, the order of reaction by the TEG supply tends to be 2. On the contrary, Be(MeCp) 2 is activated more by the AsH 3 supply, and thus, the order of reaction by AsH 3 supply tends to be 1.…”

Section: Be Doping Characteristics For the P + -Gaas Layermentioning

confidence: 99%

Sidewall GaAs tunnel junctions fabricated using molecular layer epitaxy

Ohno

Oyama

2012

Science and Technology of Advanced Materials

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In this article we review the fundamental properties and applications of sidewall GaAs tunnel junctions. Heavily impurity-doped GaAs epitaxial layers were prepared using molecular layer epitaxy (MLE), in which intermittent injections of precursors in ultrahigh vacuum were applied, and sidewall tunnel junctions were fabricated using a combination of device mesa wet etching of the GaAs MLE layer and low-temperature area-selective regrowth. The fabricated tunnel junctions on the GaAs sidewall with normal mesa orientation showed a record peak current density of 35 000 A cm −2 . They can potentially be used as terahertz devices such as a tunnel injection transit time effect diode or an ideal static induction transistor.

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Evaporation from small particles

Cited by 288 publications

References 5 publications

Radiative cooling of fullerene anions in a storage ring

Radiative cooling of fullerene anions in a storage ring

Adsorption of hydrogen on neutral and charged fullerene: Experiment and theory

Sidewall GaAs tunnel junctions fabricated using molecular layer epitaxy

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