  We describe measurements of the uniaxial magnetic anisotropy and spin-flop
rotation of the N\'eel vector in antiferromagnetic CuMnAs thin films using
neutron diffraction. The suppression of the magnetic (100) peak under magnetic
fields is observed for films as thin as 20 nm indicating that they undergo a
spin-flop transition. Good agreement is found between neutron diffraction and
electron transport measurements of the spin-flop rotation in the same layer,
with a similar shape and hysteresis of the obtained curves, while the neutron
measurements provide a quantitative determination of the spin flop extent
throughout the antiferromagnet layer.
