INFLUENCE OF LATTICE-PARAMETER AND ELECTRONIC-STRUCTURE ON THE SPIN FLUCTUATIONS IN DOPED UAL2

UAl2 is known as a typical spin fluctuation compound. We studied sampl es of U(1-x)M(x)Al(2) (M = Zr, Ti, Hf, Sc) in order to learn more abou t the parameters important for the spin fluctuations. Results of X-ray diffraction, magnetic susceptibility and specific heat measurements a re presented. The specific heat data are analyzed on the basis of the paramagnon theory. We find that a smaller lattice parameter a(0) weake ns the spin fluctuations in the case of 4-valent M = Zr, Ti, Hf, visib le in a lowered spin fluctuation temperature T-SF and a lower gamma (= lim(T-0)C/T), while for 3-valent M = Sc we observe an enhancement. We conclude that this is due to a change in the electronic structure.