  Recently has been observed for some one-dimensional models that exhibit
unexpected pseudo-transitions and quasi-phases. This pseudo-transition
resembles a first- and second-order phase transition simultaneously. One of
those models is the spin-1/2 Ising-XYZ diamond chain, composed of Ising spin
particles at the nodal sites and the Heisenberg spin particles at the
interstitial sites. Where we assume Ising-type interaction between the nodal
and interstitial sites, the Heisenberg-type interaction between interstitial
sites, and with an external magnetic field applied along the z-axis. This model
presents an exact analytical solution applying the transfer matrix technique,
which shows 3 phases at zero temperature in the vicinity of pseudo-transition.
The pseudo-transition separates quasi-phases, these quasi-phases still hold at
a finite temperature most of the pattern configurations of a true phase at zero
temperature. Here we study the quantum entanglement of pair spin particles in
the quasi-phase regions, which can be measured through the concurrence. Then we
observe an unexpected behavior in the concurrence, that is below
pseudo-critical temperature the concurrence remains almost constant up to
pseudo-critical temperature, but above the pseudo-critical temperature, the
concurrence behaves as for the standard one-dimensional spin models. Further,
we consider the entropy behavior of the system, below pseudo-critical
temperature the entropy becomes almost null, while above pseudo-critical
temperature the system exhibits standard behavior as for ordinary
one-dimensional spin models.
