Paramagnetic scattering

At the N6el temperature (3.26) wiU become zero (for T>Tn, Sj)=0) and paramagnetic scattering (3.23) is observed at higher temperatures ). The magnitude of Brillouin function and the N6el temperature may be determined from the temperature dependence of the intensity of a magnetic reflection. 

Fig. 12. Paramagnetic scattering from MnF2 [from Ref. (59)]- The data were obtained by rocking the analyzer through the elastic position with fixed scattering angle, a) Comparison of scattering for P x and PJ x. The flipper-off data are proportional to the (-(- -1-) cross...

Fig. 18. Schematic diagram of the long-wavelength elastic diffuse scattering apparatus used to study the paramagnetic scattering from ruby [Ref. (20)]...

Reference will be made later to neutron scattering studies of the state of magnetic disorder above the Curie temperature. The measured paramagnetic scattering can be expressed in terms of the correlation function M2(Q), given by... 

The paramagnetic scattering, the interatomic distances, and the C-C energy level indicate that these compounds are composed of R"", , and an (n — 2) conduction... 

The shortest R-R distances in the rare earth sesquicarbides, Rq-3Ri, are nearly 10% shorter than the shortest R R distances in the dicarbides, which are equal to their lattice parameters. Other R0-2R2 and R0-6R3 distances are also shorter than this value, indicating that there are stronger R-R interactions in the sesquicarbides than in the dicarbides. The interatomic distances in Ce2C3, particularly the Ce-Ce distances are markedly smaller than the expected values for CcjCj with the pure trivalent Ce atoms. This is in accordance with the result obtained from the paramagnetic scattering analysis (Atoji and Williams 1967). 

It may be shown that if n is the largest power of M retained in eq. (7.72) then because of the sum over M, only magnetic multipoles of order contribute to p Q). Retaining only the first three terms in eq. (7.72), we see that the paramagnetic scattering amplitude is determined only by the magnetic dipole term,... 

Fig. 7.23. Comparison of the coherent paramagnetic scattering amplitudes for H c and H c with Dirac-Fock calculations of the magnetic form factor of paramagnetic Er (after Stassis et al., 1976).

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