14
CHAPTER 3. PARAMAGNETISM OF FREE IONS
in Chapter 8). For
one has J = 9/2 and g = 8/11 (see Table 2.2.1). Furthermore,
we make use of the following values
and
At room temperature (298 K), one derives for y in Eq. (3.1.11):

Since we now have shown that
under the above conditions, it is justified to use only
the first term of the series expansion of
for small values of y
From this follows, keeping only the first term,