2 Research institute for chemistry (VUANCh) Revoluční 86, Ústí nad Labem , CR

1. Introduction

The fullerites are belonging to the superstructure of the fullerenes , the closed carbon molecules. The most expandede form from the fullerenes is the fullerene C60 containing the 60 carbon atoms in the corner of the trancated twentyfaced object, s-icosahedron (fig.1). This molecule has been firstly described in the 1985 year by Curl, Kroto and Smalley [1]. Their discoverers have been awarded in the year 1996 through the Nobel price i chemistry. The fullerene molecule has been annonced in the year 1991 as a molecule of the year. Now it is getting the object of the contemporary research. It can be said, that the fullerenes and their aggregates wil be the object of the interest in the whole third milenium. Today there are existing many pappers about fullerenes and their derivatives in all modern world languiges. The papers have been appeared as a results of the original work, over review articles also in czech [3, 4,5,6] to the popular scientific ones [7,8] to the mnographies [9,10] to the proceedings from the conference [11].

The fullerene is a has been created as superstructure of the sferical molekules of the C60 fullerene. In it the fullerene molecules are creating the closed packed layer structure with the three lazered periodicitz of the tzpe ... ABCABCABC... . It is necessary to note, that the two lazered periodicity has not been observed to this time. The Thrre layered structure is creating the face centred cubic strukture shown on the fig.2. The other layered superstructure as the hexagonal close packed struture has not been found as well as the superstructure of the higher periodicity. Because the diameter of the fullerene :sphere is approximately 0,7nm and its volume is about the 0,34 cubic nanometers and the volume of the hzdrogen atom is being is only 0,0001 cubic nanometers, it is following from this fact, that tothe fullerene molecule volume it can be placed about a thausend hzdrogen atoms. To the fullerene volume there can be implanted also another atom as it is being shown in the fig.3 where thre is an alkali metal atom in the fullerene innner. This structure has been called the fullerid. Through the modification of the fullerene there is being the possibility of the prepare the all known properties of the solids. Therefore is being the so high interest about the sesearch of all midifications of the fullerenes.In this contribution the some structure parameters as well as the some properties of the fullerite have been studied.

2. X-ray spectral analysis of the fullerite

Because the fellerene molekul can be found in the fullerite structure, which is a solid (see fig.2), it is seemeing quite naturally to measure the for example diameter and other characteristics of fullerenes on the fullerites. For the estimation of the physical properties of fullerites the first step is to measure the the chemical analysis of the fullerite probes. delivered from the firma Hoecht as a coarsegrained powder. The probes have been contained 99,78 w% of carbon and the 0,22w% has been belonged to the other elements. To the identification of the other elements he phase analysis has been made through the X-ray quantitative analysis which has been shown the following quantity of the elements in the fullerite : S 0,163 w%, Ba 0,081w%, Ar 0,0275w%, Os 0,0020w%, Fe 0,0016w%, Zn 0,0015. The rest of the elements are belomging to the light elements to the element 10, which cannot be detected through the X-ray spectral analysis. The measurements have been made on the equipment of firma Phillps PW1404 working with rhodium anode at the voltage 80kV using the germanium crystal ad the lithium fluorid one as monochromator elements using the Bragg reflexion (111) for Ge and (220) on LiF. The distribution of admixture atoms could not be determined with such a technique.

3. X-ray diffraction analysis of fullerite

To the determination of sructure parameters the X–ray diffraction technique has been used. With the diffractometer with copper Roentgen tube with monochromator and Soller screen and wave lenght 0,154nm (CuKa ) have been used. The diffraction curves are being shown on the fig.4 and 5. On the fig.5 the two difrraction curves are being represented. They are corresponding to two probes, the original and milled ones. The diffration curves of the milled fullerite are being shifted to the smaller Bragg angles that is meaning to the longer nterface distance d . The diffractograms on the fig.4,5 has been millerindexed after [12], from single reflexions the interface distances calculated and the lattice parameters.for the each diffraction line determined. The order of the lattice parameters has been labeled in the accordance with the order of the diffraction lines. The value of the single ai parameters are being as follows:: a1´= 1,64, a2=1,a3=1,316, a4=1,16, a5=1,07,a6=1, a7=1,+ě, a8=1,22 nm. From the theorwtical calculations made in [10] p.63, the C60 fullerene diameter has been calculated and obtained the value D=0,71nm. The lower measured value can be interpreted the attraction of the elastic fullerene spheres and their compressing. The different values of the fullerite lattice parameters can be explained through the geometric anisotropic sphere deformation.

4. Some phzsical properties of fullerite

In the reference [10] some different phzsical properties of the fullerite have been demonstrated.as the electrical, photoelectrical conductance and luminescence are. These properties have been found also on the our probes od the fullerite. The measurements of the fullerite resistivity have been shown the value of the order 10^14W .m and it is nearlz nonconductive. The photoconductivity stimulated throgh the nitrogene laserand crzpton discharche tube as ell as the mechanoluminescence [13] has not been observed. Because the introduced measured properties are being structure sensitive and in [10] the the compositon and admixtures have not been introduced, the different results are not being astonishing.

5. Evaluation and conclusion.

The solution of some structure parameters of the fullerite have been shown that the our fullerite has been had the the cubic face centred lattice with the lattice points created through the C60 fullerene balls. Through the acting of the attractive forces between the balls analogical to the metal bonding and elasticitz of the fullerene balls is the fulletite lattice in certain direction with the smaller ball density being deformed and the experimentally determined ball diameter 0,66nm is being smaller than theoretically one. X-ray spectral analz\ysis has been shown the presence of the admixture of the sulphure in 0,163w% and barium in 0,0810w% which the structural sensitive studied physical properties have not been influenced through.

The paper is being dedicated to the 20^th not ending she s life birthday of the dauther Magdanena Sodomkova.

5. References

[1] Kroto, H.V. et al.: Nature 318 (1985) 162

[2] Sodomka,L.: Nobelova ca ya objev fulerenu. MFI 7 (1997) 63

Sodomka,L., Sodomkova,,M.: Nobelovy ceny za fyziku. SetOut Praha 1997

[3] Matyáš,M.: Fullereny a fullerity. PMFA (1992)288

[4] Jech,Č.: Fullerenová allotropní forma uhlíku. Čs.čas.Fyz. 42(1992)337

[5] Kraetchmer, W. AnH- Magazin NO.62 Dezember 1993, p.11[6]

[7] Sodomka,L., Sodomka,J.: Diamanty a ježci vkleci. T97 40(1997)22

[8] Valenta , J. > Nejkulat2j39 miolekula. Vesmír 76(1997)65

[9] Koruga,G., et al.: Felllerene C60. North Holland Amsterodam 1963.

[10] Dresselhaus,M.S., et al.: Science of fullerenes and carbon nanotubes. Academic Press, New York 1996

[11] Andreoni, W.: The chemical physics of fullerenes 19 (and 5) years later. NATO ASI series E:Applied Science , Kluwer academic Publisher, Dornrecht 1996

[12]Sodomka,L.: Rentgenová difraktografie pevných látek. SNTL Praha 1960.

[13]Sodomka,L.:Mechanoluminiscence a její použití. Academia Praha 1985

Fig.1. Fullerene C60 Fig. 2. Fullerite

Fig.3. Fullerid with kalium atom in its inner.

Fig. 4. Diffractograms of milled fullerite

Fig. 5. Diffractograms of the original and milled fullerite