LAUSR

By using Shubnikov-de Haas oscillations in crossed magnetic fields, we measured the temperature dependence of the renormalized spin susceptibility χi∗(T)$\chi _{i}^{*}(T)$ for strongly interacting itinerant 2D electrons in silicon. The weak δχi∗(T)$\delta \chi _{i}^{*}(T)$ dependence, only a few percent over the range T = (0.1 − 1) K, agrees qualitatively with the predicted interaction corrections. However, in strong in-plane magnetic fields, the χ∗(T) dependence does not vanish or weaken as expected for the interaction corrections. We found that the susceptibility variations are correlated with the T-dependence of the density of itinerant electrons extracted from the magnetooscillation period. We conclude therefore that the χi∗(T)$\chi _{i}^{*}(T)$ dependence is affected by a T-dependent exchange of electrons between the subsystems of itinerant and localized electrons which are in thermodynamic equilibrium.