The wavevector and energy dependence of the paramagnetic response in the normal phase of the Heavy Fermion system UBe13 has been investigated between 10 K and 300 K using polarized neutrons and polarization analysis. At 10 K the response was found to be enhanced at non zero wave-vectors indicating the presence of strong antiferromagnetic correlations. The peaks in the scattering occured at positions expected for incipient type G antiferromagnetism of the simple cubic uranium sublattice. At room temperature the spatial correlations completely disappeared and the response was wave vector independent. Constant Q scans carried out at 10 K confirmed the Lorentzian dependence proposed by Goldman et al. [1]. © 1986.

The static magnetic field induced magnetisation densities of two uranium based heavy-fermion systems have been determined in spin polarised neutron scattering experiments at temperatures of T = 5K and T = 10K, respectively. Both compounds show a significantly different magnetisation density. The various contributions are identified. In UPt3 the polarisation of conduction electrons is important, but in contrast the magnetisation density in UBe13 is observed to be of a pure uranium 5f-electron character with no indication of any conduction electron contribution due to polarization by the external magnetic field. Both heavy-fermion compounds have in common a small value of the aligned 5f-electron magnetic moment which is well described by a spherically symmetric model. However, UPt3 and UBe13 differ significantly in the contributions of the conductions electrons. © 1991.