A double-temperature-gradient technique for the growth of single-crystal fullerites from the vapor phase

Haluška, M.; Kuzmany, H.; Vybornov, M.; Rogl, P.; Fejdi, P.

doi:10.1007/bf00539469

Cited by 142 publications

(35 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The light intensities were 3.1 mW/mm 2 and 1.0 mW/mm 2 , which were lower than that of the 670-nm laser. Only cracked surfaces are observed, without any fringes, which is similar to the optical microscopic observations of Haluska et al [30] and of Verheijen et al [31]. These cracks sustain the directional characteristics of each face: that is, cracking occurs along the [010] directions on the (001) faces and along the [112] directions on the (111) faces, similar to the directions of the fringes on the reconstructed surfaces.…”

Section: Resultssupporting

confidence: 74%

AFM observation of surface reconstruction of C 60 single crystals

Kim

Jiang

Iyoda

et al. 1998

Applied Physics A: Materials Science & Processing

View full text Add to dashboard Cite

We report an atomic force microscopic (AFM) examination of the photo-induced surface reconstruction of C 60 single crystals. The (111) and the (001) faces of C 60 single crystals were illuminated with photons with energies below the band gap (generation of Frenkel-type excitons) or above the band gap. In the case of sub-band-gap illumination, reconstructed surfaces formed on the crystals. The reconstruction was represented by fringes running in the [112] and [010] directions on the (111) and (001) surfaces, respectively. As a result of supra-band-gap illumination, however, there appeared only cracks, without any fringes, which were oriented in directions characteristic of each face. The results suggest that the photo-induced surface reconstruction of C 60 single crystals is induced via the recombination of Frenkeltype excitons.Since the discovery of C 60 [1], there have been numerous investigations on its structural and optical properties in the solid state [2]. Molecules of C 60 condense at room temperature into a face-centered cubic (fcc) structure held by rather weak intermolecular van der Waals forces [3]. A great number of studies of the surface morphology of epitaxial fullerene films on various types of substrate [4,5] have been conducted with atomic force microscopy (AFM) and/or scanning tunneling microscopy (STM). We recently also carried out AFM studies of the morphology and surface dislocations of fullerene single crystals and epitaxial films [6][7][8][9][10][11]. The reconstructed (0001) face of C 70 single crystals exhibited a long-range periodic array of partial dislocation fringes [8]. In a related fashion, AFM images of the reconstructed surface of C 60 epitaxial films on KBr(001) substrates showed many fringes in the equivalent [110] directions on the fcc(111) plane [11]. In the latter case, molecular-resolution images revealed that the reconstructed surface is contracted by ca. 3% in the [112] direction. Both of these observations suggest a stacking-faultdomain model involving periodic transitions between fcc and hexagonal-closed packed (hcp) structures in the surface layer.Solid C 60 is a molecular semiconductor with a band gap of 2.3 eV [12], and weak optical absorption in the range of 1.6 to 2.2 eV, which corresponds to Frenkel-type excitons [12,13]. Previous to the present work, several reports have appeared concerning photo-transformations of solid C 60 by optical illumination. First, the irradiation of oxygen-free C 60 films with an Ar-ion laser at 514.5 nm (2.41 eV) and 488.0 nm (2.54 eV) was focused to initiate the irreversible polymerization of C 60 [14][15][16]. Second, in the presence of oxygen, C 60 undergoes oxidation upon uv light irradiation [17,18]. Both the photo-induced polymerization and the photoinduced oxidation processes are initiated by supra-band-gap illumination. In this paper, we report an AFM investigation of photo-induced structural transformations of C 60 singlecrystal surfaces using both sub-band-gap and supra-band-gap illumination.

show abstract

Section: Resultssupporting

confidence: 74%

AFM observation of surface reconstruction of C 60 single crystals

Kim

Jiang

Iyoda

et al. 1998

Applied Physics A: Materials Science & Processing

View full text Add to dashboard Cite

show abstract

“…Fcc and hcp structures are both stable at room temperature, whereas, from the energetic point of view, the fcc structure is much more stable. Moreover, the differences in the structure result from the different conditions under which crystals grow (Haluska et al, 1993;Ven Tendeloo et al, 1991;Verheijen et al, 1993). To some extent, (0001) hcp face can be considered as the structure defect caused by the stacking faults of (111) fcc face in fcc C 60 crystals.…”

Section: Introductionmentioning

confidence: 99%

High resolution electron microscopy investigations of interface and other structure defects in some ceramics

Wen

Liu

1998

Microsc. Res. Tech.

View full text Add to dashboard Cite

“…For the o-Rb 1 C 60 samples, the surface of C 60 single crystals (grown by a double temperature gradient technique [25]) was doped in situ in an IR-spectrometer as described elsewhere [9]. The undoped part of the single crystals was subsequently dissolved in toluene to give free-standing films of Rb 1 C 60 .…”

Section: Methodsmentioning

confidence: 99%

The electronic structure of polymerized fullerenes and dimerized heterofullerenes

Pichler

Knupfer²,

Golden³

et al. 1997

Applied Physics A: Materials Science & Processing

Self Cite

View full text Add to dashboard Cite

The electronic structure of polymerized fullerenes and dimerized heterofullerenes Pichler, T.; Knupfer, M.; Golden, M.S.; Fink, J.; Winter, J; Haluska, M.; Kuzmany, H.; Keshavarz, K.; Bellavia-Lund, C.; Sastre, A. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Abstract. We present studies of the electronic structure of polymerized orthorhombic Rb 1 C 60 and dimerised C 59 N using electron energy-loss spectroscopy in transmission. From the C1s excitation spectra a reduced density of π* states is observed for polymerized Rb 1 C 60 . This is in contrast to (C 59 N) 2 and can be explained by the different type of 'doping' and by the different bonding between the fullerene molecules in the two systems. Additional information about the optical properties was obtained from the low energy loss function. Using a Kramers-Kronig analysis, the dielectric function, (ε), and the optical conductivity, (σ), have been derived. ε(0) and the onset of the spectral weight have been compared between the polymer, the dimer and C 60 . This onset of spectral weight is found to be at 1.2 and 1.4 eV for o-Rb 1 C 60 and for (C 59 N) 2 , respectively.

show abstract

A double-temperature-gradient technique for the growth of single-crystal fullerites from the vapor phase

Cited by 142 publications

References 21 publications

AFM observation of surface reconstruction of C 60 single crystals

AFM observation of surface reconstruction of C 60 single crystals

High resolution electron microscopy investigations of interface and other structure defects in some ceramics

The electronic structure of polymerized fullerenes and dimerized heterofullerenes

Contact Info

Product

Resources

About