  The van der Waals class of materials offer an approach to two-dimensional
magnetism as their spin fluctuations can be tuned upon exfoliation of layers.
Moreover, it has recently been shown that spin-lattice coupling and long-range
magnetic ordering can be modified with pressure in van der Waals materials. In
this work, the magnetic properties of quasi two-dimensional CrBr3 are reported
applying hydrostatic pressure. The application of pressure (0 - 0.8 GPa) shows
a 72 % decrease in saturation magnetization with small decrease in the Curie
temperature from 33 to 29 K. Density functional theory calculations with
pressure up to 1 GPa show a reduction in volume and interplanar distance as
pressure increases. To further understand magnetic properties with applied
pressure, the magnetocrystalline anisotropy energy (MAE) and exchange coupling
parameter (J) are calculated. There is minimal decrease in MAE and the first
nearest neighbor interaction (J1) (U = 2.7 eV and J = 0.7 eV), shows an
increase in J1 with respect to pressure. Overall, CrBr3 displays ferromagnetic
interlayer coupling and the calculated exchange coupling and MAE parameters
match well with the observations from the experimental work.
