Antiferromagnetic CuMnAs thin films have attracted attention since the
discovery of the manipulation of their magnetic structure via electrical,
optical, and terahertz pulses of electric fields, enabling convenient
approaches to the switching between magnetoresistive states of the film for the
information storage. However, the magnetic structure and, thus, the efficiency
of the manipulation can be affected by the film morphology and growth defects.
In this study, we investigate the properties of CuMnAs thin films by probing
the defect-related uniaxial anisotropy of electric conductivity by contact-free
terahertz transmission spectroscopy. We show that the terahertz measurements
conveniently detect the conductivity anisotropy, that are consistent with
conventional DC Hall-bar measurements. Moreover, the terahertz technique allows
for considerably finer determination of anisotropy axes and it is less
sensitive to the local film degradation. Thanks to the averaging over a large
detection area, the THz probing also allows for an analysis of strongly
non-uniform thin films. Using scanning near-field terahertz and electron
microscopies, we relate the observed anisotropic conductivity of CuMnAs to the
elongation and orientation of growth defects, which influence the local
microscopic conductivity. We also demonstrate control over the morphology of
defects by using vicinal substrates.Comment: 33 pages, 16 figure