1,2,3-Dithiazolyl and 1,2,35-Dithiadiazolyl Radicals as Spin-Bearing ...

linear relationship shown in Figure 1-1 with χT = C (J = 0). Interactions between
unpaired electrons result in deviations from the ideal Curie Law which are more
prominent at low temperatures. Real materials do not exhibit true Curie magnetism, and
are instead defined as having near Curie behaviour. Therefore a better way of describing
these types of systems in a higher temperature regime is achieved by using the Curie-
Weiss law which adds the additional parameter Θ and is written as:
(1.4)
where Θ is the Weiss constant. This constant is used when the temperature is
much higher than the Curie temperature which is the temperature below which a
compound will exhibit spontaneous magnetization. At higher temperatures the
interactions with neighbouring magnetic domains must be considered and the value of Θ
will provide some indication as to the nature of these interactions. If Θ = 0 then the
equation becomes 1.3 and the material is considered paramagnetic. When Θ > 0 then the
interaction is ferromagnetic and when Θ < 0 the interaction is antiferromagnetic.
Bohr magnetons (β or μ B ) are the fundamental quantum of magnetic moment and has
a value of 4.66864374 × 10 -5 cm -1 G -1 such that
and:
(1.5)
according to:
It is also important that the value of μ is related to the spin quantum number S
(1.6)
3