  Magnetic excitations in layered magnetic materials that can be thinned down
the two-dimensional (2D) monolayer limit are of high interest from a
fundamental point of view and for applications perspectives. Raman scattering
has played a crucial role in exploring the properties of magnetic layered
materials and, even-though it is essentially a probe of lattice vibrations, it
can reflect magnetic ordering in solids through the spin-phonon interaction or
through the observation of magnon excitations. In bulk CrSBr, a layered A type
antiferromagnet (AF), we show that the magnetic ordering can be directly
observed in the temperature dependence of the Raman scattering response i)
through the variations of the scattered intensities, ii) through the activation
of new phonon lines reflecting the change of symmetry with the appearance of
the additional magnetic periodicity, and iii) through the observation, below
the Neel temperature (TN) of second order Raman scattering processes. We
additionally show that the three different magnetic phases encountered in
CrSBr, including the recently identified low temperature phase, have a
particular Raman scattering signature. This work demonstrates that magnetic
ordering can be observed directly in the Raman scattering response of bulk
CrSBr with in-plane magnetization, and that it can provide a unique insight
into the magnetic phases encountered in magnetic layered materials.
