  Strain engineering is a powerful mean for tuning the various functionalities
of ABO3 perovskite oxide thin films. Rare-earth orthoferrite RFeO3 materials
such as NdFeO3 (NFO) are of prime interest because of their intriguing magnetic
properties as well as their technological potential applications especially as
thin films. Here, using a large set of complementary and advanced techniques,
we show that NFO epitaxial thin films, successfully grown by pulsed laser
deposition on (001)-SrTiO3, show a strong magnetic anisotropy below a critical
thickness tc of 54 nm, associated with the occurrence of structural
modifications related to symmetry and domain pattern changes. By varying the
tensile misfit strain through the decrease of film thickness below tc, the
amplitudes of in and out-of-plane magnetization can be continuously tuned while
their ratio stays constant. Furthermore, different low-temperature magnetic
behaviors are evidenced for strained and relaxed films, suggesting that the
strain-induced structural state impacts the magnetic phase stability.
