The thermodynamics of copper-zinc alloys (brass) was subject
of numerous investigations. Brass is characterised by an excess
enthalpy and excess entropy of mixing, both of which are negative.
The enthalpic data were measured by solution calorimetry e.g.,
[1–3] and based on chemical potential data calculated from phase
equilibrium experiments e.g., [4–6], the excess entropy of mixing
could be evaluated e.g., [7–9]. This excess entropy contains both,
the vibrational and the configurational parts. The excess
vibrational entropy, defined as the deviation from the entropy of
a mechanical mixture of the end members A and B (i.e.,
S
mechmix
m
¼ X
A
S
A
m
þ X
B
S
B
m
), can be determined by measuring the
low temperature heat capacity (5 to 300 K) versus composition
behaviour. The determination of the excess configurational
entropy, i.e., the excess entropy coming from non-random atomic
distributions and defects, is much more difficult. Here, neutron
scattering investigations together with computer simulations are
normally used. If, however, reliable data of the total excess entropy
(from enthalpic and chemical potential data) are available, the
measurement of the excess vibrational entropy enables the
determination of the excess configurational entropy simply by subtraction.
Since configurational and vibrational entropies may have
The thermodynamics of copper-zinc alloys (brass) was subject
of numerous investigations. Brass is characterised by an excess
enthalpy and excess entropy of mixing, both of which are negative.
The enthalpic data were measured by solution calorimetry e.g.,
[1–3] and based on chemical potential data calculated from phase
equilibrium experiments e.g., [4–6], the excess entropy of mixing
could be evaluated e.g., [7–9]. This excess entropy contains both,
the vibrational and the configurational parts. The excess
vibrational entropy, defined as the deviation from the entropy of
a mechanical mixture of the end members A and B (i.e.,
S
mechmix
m
¼ X
A
S
A
m
þ X
B
S
B
m
), can be determined by measuring the
low temperature heat capacity (5 to 300 K) versus composition
behaviour. The determination of the excess configurational
entropy, i.e., the excess entropy coming from non-random atomic
distributions and defects, is much more difficult. Here, neutron
scattering investigations together with computer simulations are
normally used. If, however, reliable data of the total excess entropy
(from enthalpic and chemical potential data) are available, the
measurement of the excess vibrational entropy enables the
determination of the excess configurational entropy simply by subtraction.
Since configurational and vibrational entropies may have
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