A series of di-gadolinium endohedrals that extends from Gd(2)C(90) to Gd(2)C(124) has been detected by mass spectrometry of the o-dichlorobenzene extract of the carbon soot produced by direct current arcing of graphite rods filled with a mixture of Gd(2)O(3) and graphite powder. Chromatographic separation has led to the isolation of pure samples of two isomers of Gd(2)C(94) and the complete series from Gd(2)C(96) to Gd(2)C(106). Endohedral fullerenes of the type M(2)C(2n) can exist as the conventional endohedral, M(2)@C(2n), or as the carbide-containing endohedral, M(2)C(2)@C(2n-2). Crystallographic characterization of the more rapidly eluting isomer of Gd(2)C(94) reveals that it possesses the carbide structure, Gd(2)C(2)@D(3)(85)-C(92). Computational studies suggest that the more slowly eluting isomer of Gd(2)C(94) may be a conventional endohedral, Gd(2)@C(2)(121)-C(94).

CONTENTS 1. INTRODUCTION 2. ATOMIC (CHEMICAL) DISORDERING OF INTERMETALLIC COMPOUNDS IN THE EARLY STAGE OF BALL MILLING 2.1. Experimental procedures 2.2. Anti-site disorder in B2 compounds 2.2.1. Thermal disorder in B2 compounds 2.2.2. Mechanically induced disorder in B2 compounds 2.3. Anti-site disorder in Llr compounds 2.4. Anti-site disorder in AI5 compounds 2.4.1. Introduction 2.4.2. Thermal disorder and disorder by irradiation in AI5 compounds 2.4.3. Mechanically induced disorder in AI5 compounds 2.5. Triple-defect disorder in group VIII-group IIIA compounds crystallising in the B2 structure 2.5.1. Introduction 25.2. Thermal disorder in VIII-IIIA compounds 2.5.3. Mechanically induced disorder in VIII-IIIA compounds 2.6. Atomic disorder in B8 compounds 2.6.1. Introduction 2.6.2. Mechanically induced disorder in B8t compounds with composition T, sZ 2.6.3. Mechanically induced disorder in B8r compounds with composition TJZ and related orthorhombic phases 2.7. Discussion 3. PHASE TRANSFORMATIONS IN INTERMETALLIC COMPOUNDS INDUCED BY BALL MILLING 3.1. Amorphisation 3.2. Phase transformations to the solid solution: The Au-Nb system 3.3. Phase transformations in the Ni-V system 3.4. Phase transformations in compounds with the B82 structure and related orthorhombic structure 3.5. Mechanically induced disorder and phase transformations in Llr compounds 3.6. Phase transformations in a-phases 3.7. Prediction of phase transformations in intermetallic compounds induced by milling 3.8. Discussion 4. NEW MATERIALS SYNTHESISED BY MECHANICAL MILLING 4.1. Introduction 4.2. Novel spin-glass materials by ball milling of intermetallic compounds

An extensive series of soluble dilanthanum endohedral fullerenes that extends from La(2)C(90) to La(2)C(138) has been discovered. The most abundant of these, the nanotubular La(2)@D(5)(450)-C(100), has been isolated in pure form and characterized by single-crystal X-ray diffraction.

We report the isolation and structural characterization of the nanocapsule Sm 2 @D 3d (822)-C 104 . This remarkable molecule is the largest endohedral fullerene to be crystallographically characterized to date and is nearly twice the size of the prototypical C 60 . The carbon cages in endohedral fullerenes involving metal atom encapsulation are generally larger than C 60 . Considerable effort has been expended in characterizing endohedral fullerenes with 80, 82, or 84 carbon atoms. [1] Endohedral fullerenes containing M 3 N units can be obtained in yields that are better than those of endohedrals with only metal atoms inside. [2,3] For endohedrals of the type M 3 N@C 2n , metal atom size affects the size of the fullerene cage that forms. [4][5][6] With a small metal atom like scandium, the family of endohedrals Sc 3 N@C 80 (I h and D 5h isomers), Sc 3 N@D 3h -C 78 , and Sc 3 N@D 3 -C 68 form.[2] But with a bigger metal atom, cerium, Echegoyen and co-workers observed the formation of cages as large as Ce 3 N@C 104 . [7,8] Large fullerene cages can also form around only one or two metal atoms. A series of endohedrals containing two gadolinium atoms extending from Gd 2 C 90 to Gd 2 C 124 has been detected and pure samples of two isomers of Gd 2 C 94 and the complete series from Gd 2 C 96 to Gd 2 C 106 have been obtained.[9] Of these, Gd 2 C 2 @D 3 (85)-C 92 has been structurally characterized by X-ray diffraction. [9] Prior to the present work, the largest endohedral fullerenes to be fully structurally characterized were the monometallic endohedrals, Tm@C 3v -C 94 and Ca@C 3v -C 94 .[10] Poblet and coworkers have examined the possible structures of carbon cages in the size range C 92 to C 100 , in which there is a formal transfer of six electrons from a M 3 N cluster or a M 2 unit to the carbon cage. They noted the remarkable properties and stability of the D 5 (450)-C 100 cage, which is related to the I h and D 5h isomers of C 80 through dividing the cage in half perpendicular to the five-fold axis and adding an array of 20 carbon atoms between the two halves. [11] Carbon soot containing samarium-based endohedral fullerenes was obtained by vaporizing a graphite rod filled with Sm 2 O 3 and graphite powder in an electric arc as outlined earlier.[12] The carbon soot was extracted with o-dichlorobenzene and the soluble extract was subjected to a four-stage high pressure liquid chromatographic (HPLC) isolation process. Three individual isomers of Sm 2 @C 104 were separated and purified. These isomers are labeled Sm 2 @C 104 (I), Sm 2 @C 104 (II), and Sm 2 @C 104 (III) in order of their elution times (29.4 (I), 30.0 (II) and 31.5 min (III), Buckyprep column, chlorobenzene eluent) during chromatography. The relative abundances of the isolated isomers are 1 (I):0.6 (II):0.2 (III). UV/Vis/NIR absorption spectra of the individual isomers are shown in Figure 1. Figure 2 shows the laser-desorption time-of-flight (LD-TOF) mass spectrum of the purified sample of the first isomer to elute, Sm 2 @C 104 (I), which was utilized in ...