ESR study of the formation of superconducting Rb[sub 3]C[sub 60] from solution

Journal Article · Sat May 01 04:00:00 EDT 1993 · Chemistry of Materials; (United States)

DOI:https://doi.org/10.1021/cm00029a025· OSTI ID:6096277

Schlueter, J A; Wang, H H; Lathrop, M W; Geiser, U; Carlson, K D; Dudek, J D; Yaconi, G A; Williams, J M ^[1]

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1. Argonne National Laboratory, IL (United States)

A solution-based procedure, requiring reaction times less than 2 h, has been developed for the rapid preparation of Rb[sub 3]C[sub 60] (T[sub c] onset = 29.0 [plus minus] 0.1 K) with superconducting shielding fractions near 50%. A 9:1 (vol) toluene/benzonitrile solvent system was used, which prevents premature precipitation of C[sub 60] as a monoanion. The Rb[sub x]C[sub 60] material prepared in this manner from solution has been characterized by an ESR line-shape analysis at room temperature. In rigorously dried toluene, the primary product is RbC[sub 60], but as the solvent polarity is increased with the addition of benzonitrile as a [open quotes]redox catalyst[close quotes], a greater fraction of superconducting Rb[sub 3]C[sub 60] is precipitated. The different room-temperature ESR line widths and integrated spin susceptibilities of these two products are used to quantify the relative yields of these two C[sub 60][sup n-] species. The superconducting shielding fraction of the as formed [open quotes]Rb[sub x]C[sub 60][close quotes] product is found to correlate linearly with the Rb[sub 3]C[sub 60] content obtained from ESR line-shape analysis, confirming that Rb[sub 3]C[sub 60] is the only superconducting component prepared via this solution phase technique. ESR analysis revealed that Rb[sub 3]C[sub 60] samples (with shielding fractions near 100%) prepared by the conventional vapor phase technique contained a few percent RbC[sub 60] X-ray powder diffraction confirmed the presence of trace amounts of RbCN in the solution-phase prepared materials. 40 refs., 8 figs., 1 tab.

• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6096277
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 5:5; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
360606 -- Other Materials-- Physical Properties-- (1992-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
CARBON
CHEMICAL PREPARATION
CHEMICAL REACTION YIELD
COHERENT SCATTERING
DIFFRACTION
ELECTRON SPIN RESONANCE
ELEMENTS
FULLERENES
LINE WIDTHS
MAGNETIC RESONANCE
NONMETALS
RESONANCE
RUBIDIUM COMPOUNDS
SCATTERING
SUPERCONDUCTORS
SYNTHESIS
X-RAY DIFFRACTION
YIELDS