  It was shown earlier that applying a magnetic field during the growth of
Sr$_2$IrO$_4$, also known as "field-alteration", induces significant changes to
its structural, magnetic, and transport properties. However, the microscopic
nature of these changes is enigmatic. In this study, we employed resonant
elastic and inelastic x-ray scattering, as well as Raman scattering, to
investigate samples from two batches of Sr$_2$IrO$_4$ grown in magnetic fields
of different strengths. Our findings reveal that samples grown in a weaker
magnetic field have similar magnetic order to non-altered samples, whereas
those grown in a stronger field show a different stacking of weak in-plane
ferromagnetic moments. Additionally, we observed significant softening and
broadening of select Raman-active phonons in the field altered samples, with a
stronger effect in the samples grown in the stronger field. We discuss insights
that our results provide into the microscopic nature of field-alteration in
Sr$_2$IrO$_4$.
