Knight shifts and magnetic susceptibilities of the intermetallic compounds CeCu4 and CeCu5

The magnetic susceptibility and Knight shift of the compounds CeCu₄ and CeCu₅ have been measured over the temperature ranges 80–800 and 140–400 K, respectively. The most important contributions to the magnetic susceptibility are the Curie-Weiss term, expressing the paramagnetism of the localized ?-electrons, and a temperature independent term, which have both been determined. The phenomenological exchange integral F_s? between the 4?-electron spins and conduction electron spins was found to be ?10.43× 10^?3 eV for CeCu₄ and 3.9 × 10^?3 eV for CeCu₅. A reversal in the sign of the s?? coupling for CeCu₅ is noted.