Jae Gil Kim^a, Eok Kyun Lee^a and Soonchil Lee^b

^a Department of Chemistry, Korea Advanced Institute of Science and Technology, 373-1 Gusongdong, Yusongku, Daejon, Korea
^b Department of Physics, Korea Advanced Institute of Science and Technology, 373-1 Gusongdong, Yusongku, Daejon, Korea

We develop a method that provides an analytical expression of the free-electron spin susceptibility for arbitrary temperature. The result can be further reduced by using the low-temperature approximation, which shows that the oscillation decays exponentially as exp(- pi T'kFr) in the long-range limit, and the wave number of the oscillation varies as k0~kF[1-( pi 2/12)T'2], where T' is the normalized temperature with respect to the Fermi energy. The result contradicts what Darby has proposed, especially in the long-range region. On the other hand, in the short-range region, where the Sommerfeld expansion method is valid, numerical study shows that Darby's result agrees with ours fairly well.