  Crystallographic anisotropy of the spin-dependent conductivity tensor can be
exploited to generate transverse spin-polarized current in a ferromagnetic
film. This ferromagnetic spin Hall effect is analogous to the spin-splitting
effect in altermagnets and does not require spin-orbit coupling.
First-principles screening of 41 non-cubic ferromagnets revealed that many of
them, when grown as a single crystal with tilted crystallographic axes, can
exhibit large spin Hall angles comparable with the best available
spin-orbit-driven spin Hall sources. Macroscopic spin Hall effect is possible
for uniformly magnetized ferromagnetic films grown on some low-symmetry
substrates with epitaxial relations that prevent cancellation of contributions
from different orientation domains. Macroscopic response is also possible for
any substrate if magnetocrystalline anisotropy is strong enough to lock the
magnetization to the crystallographic axes in different orientation domains.
