Susceptibility of Magnetic Graphite-CoCl2 Intercalation Compounds

1982 ◽  
Vol 20 ◽  
Author(s):  
M Elahy ◽  
G. Dresselhaus
Keyword(s):  
Magnetic Susceptibility ◽  
Temperature Dependence ◽  
Theoretical Calculations ◽  
Experimental Results ◽  
Intercalation Compounds ◽  
Two Dimensional ◽  
Graphite Intercalation Compounds ◽  
Magnetic Systems ◽  
Planar Model ◽  
Graphite Intercalation

ABSTRACTPrecise measurements of the temperature dependence of the magnetic susceptibility for stage 2 and 5 graphite-CoCl2 intercalation compounds are reported. Comparison of the experimental results with theoretical calculations based on a two-dimensional planar model show agreement with theory, suggesting that graphite intercalation compounds represent ideal two-dimensional magnetic systems.

Structural and magnetic properties of random mixture graphite intercalation compounds

1990 ◽  
Vol 5 (2) ◽  
pp. 422-434 ◽  
Author(s):  
Masatsugu Suzuki ◽  
Louis J. Santodonato ◽  
Mildred Yeh ◽  
Samuel M. Sampere ◽  
Andrew V. Smith ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Intercalation Compounds ◽  
Ferromagnetic Phase ◽  
Two Dimensional ◽  
Graphite Intercalation Compounds ◽  
Weiss Temperature ◽  
Graphite Intercalation ◽  
Co Concentration ◽  
Structural And Magnetic Properties

The structural and magnetic properties of the stage 2 CocNi1−cCl2- and COcFe1−cCl2-graphite intercalation compounds (GICs) for 0 ≤ c ≤ 1 have been studied by x-ray scattering and dc magnetic susceptibility. The stage 2 CocNi1−cCl2-GICs approximate two-dimensional randomly-mixed ferromagnets with XY spin symmetry. The average effective magnetic moment Peff, the Curie-Weiss temperature θ, and the paramagnetic-to-ferromagnetic phase transition temperature Tc have been determined as continuously varying functions of Co concentration c. They indicate that the Co2+ and Ni2+ spins are randomly distributed on the triangular lattice sites of each intercalate layer. They also show that the intraplanar exchange interaction J(Co–Ni) between the Co2+ and Ni2+ spins is enhanced and is larger than the interaction J(Co–Co) between two Co2+ spins and J(Ni–Ni) between two Ni2+ spins. This enhanced interaction, J(Co–Ni), can be expressed as J(Co–Ni) = 1.28 [J(Co–Co) · J(Ni–Ni)]1/2. The stage 2 CocFc1−cCl2-GICs approximate two-dimensional randomly mixed ferromagnets with competing spin anisotropy. The dc magnetic susceptibility results suggest that Co2+, Fe3+ rather than Fe2+ are distributed in the intercalate layer. The repeat distance along the c-axis (d-spacing) versus Co concentration deviates from Vegard's law which states that the d-spacing is proportional to Co concentration. The broad peak of d-spacing observed at c = 0.75 is discussed in terms of the double layer model developed by Jin and Mahanti.

Graphite Intercalation Compounds and Applications

2003 ◽  
Author(s):  
Toshiaki Enoki ◽  
Morinobu Endo ◽  
Masatsugu Suzuki
Keyword(s):  
Electronic Structures ◽  
Electronic Materials ◽  
Structural Features ◽  
Intercalation Compounds ◽  
Two Dimensional ◽  
Graphite Intercalation Compounds ◽  
Magnetic Systems ◽  
Graphite Intercalation ◽  
Electron Transport Properties ◽  
Graphite Fibers

Graphite intercalation compounds are a new class of electronic materials that are classified as graphite-based host guest systems. They have specific structural features based on the alternating stacking of graphite and guest intercalate sheets. The electronic structures show two-dimensional metallic properties with a large variety of features including superconductivity. They are also interesting from the point of two-dimensional magnetic systems. This book presents the synthesis, crystal structures, phase transitions, lattice dynamics, electronic structures, electron transport properties, magnetic properties, surface phenomena, and applications of graphite intercalation compounds. The applications covered include batteries, highly conductive graphite fibers, exfoliated graphite and intercalated fullerenes and nanotubes.

Large anisotropy and stage dependence of the magnetic susceptibility of alkali-graphite intercalation compounds

1979 ◽  
Vol 20 (12) ◽  
pp. 4883-4888 ◽  
Author(s):  
F. J. DiSalvo ◽  
S. A. Safran ◽  
R. C. Haddon ◽  
J. V. Waszczak ◽  
J. E. Fischer
Keyword(s):  
Magnetic Susceptibility ◽  
Intercalation Compounds ◽  
Graphite Intercalation Compounds ◽  
Graphite Intercalation ◽  
Large Anisotropy

A Structural Analysis Method for Graphite Intercalation Compounds

2000 ◽  
Vol 658 ◽  
Author(s):  
Tatsuo Nakazawa ◽  
Kyoichi Oshida ◽  
Takashi Miyazaki ◽  
Morinobu Endo ◽  
Mildred S. Dresselhaus
Keyword(s):  
Image Analysis ◽  
Electronic Materials ◽  
Stage Structure ◽  
Intercalation Compounds ◽  
Two Dimensional ◽  
Analysis Method ◽  
Graphite Intercalation Compounds ◽  
Graphite Intercalation ◽  
Lattice Images ◽  
Stage 1

ABSTRACTStudy of the microstructure of electronic materials can be enhanced by using high resolution transmission electron microscopy (TEM) combined with the technique of digitized image analysis. We show here a practical image analysis method for the microstructures of acceptor graphite intercalation compounds (GICs) with CuCl2 and FeCl3 intercalates. The two dimensional fast Fourier transform (2D-FFT) was used for the frequency analysis of the TEM pictures. It is found that the lattice images of CuCl2-GICs consist of different frequency images corresponding to specific frequencies. The detailed features of the stage-1 structure of the FeCl3-GICs is extracted quantitatively by this method from a relatively indistinct TEM picture. The stage structure of the CuCl2- and FeCl3-GICs are further investigated by analyzing the reconstruction of the TEM images by means of the two dimensional inverse FFT (2D-IFFT).

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