Onion-like nanoscale structures and fullerene-type cages formed by electron irradiation on turbostratic B{sub x}C{sub 1{minus}x} (x<0.2)

Book · Thu Dec 31 04:00:00 EST 1998

OSTI ID:323491

Golberg, D; Bando, Y; Kurashima, K; Sasaki, T ^[1]

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1. National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan)

Flakes of CVD grown B{sub x}C{sub 1{minus}x} (x<0.2) films were exposed to intense electron irradiation (flux density up to {approximately}100 A/cm{sup 2}) in a 300 kV high resolution electron microscope equipped with a field emission gun. The starting flakes revealed a turbostratic B{sub x}C{sub 1{minus}x} structure. The composition of the starting materials and irradiated products was determined by using electron energy loss spectroscopy (EELS). Depending on the electron dose applied, irradiation of the turbostratic material led to formation of soap-bubble-like irregularly-shaped objects (linear dimensions of {approximately}2--5 nm), onion- and semi-onion-like structures (d{approximately}10nm), nested fullerenes (3--14 shells) and elementary fullerene-type cages (d{approximately}0.7 nm). It is thought that these curled and closed nanostructures arise from a continuous bending of the hexagonal B{sub x}C{sub 1{minus}x} sheets under electron irradiation. Finally, some possible structural models of B{sub x}C{sub 1{minus}x} fullerenes are considered.

• OSTI ID: 323491
• Report Number(s): CONF-971201--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON CARBIDES
CHEMICAL COMPOSITION
CRYSTAL STRUCTURE
ELECTRON BEAMS
EXPERIMENTAL DATA
FULLERENES
PHYSICAL RADIATION EFFECTS
SPECTROSCOPY