  The weak ferromagnet FeBO$_3$ is well known for being a unique system for
modelling and testing magnetic dynamics primarily due to relatively simple and
localized magnetic structure and its interesting spin wave dynamics. At room
temperature, it has slightly canted iron moments lying in the a-b plane that
result in a strong antiferromagnetic moment and a weak ferromagnetic moment,
which results in pronounced ferromagnetic and antiferromagnetic spin modes.
However, some previous studies have shown unusual low-temperature behavior that
suggests a phase transition. By performing low-temperature magnetization
measurements, both in bulk and on the mesoscale, we have observed a low
temperature magnetic texture in this material in which a large c-axis
magnetization occurs. Magnetic fields along the c-axis as high as 1300 Oe were
observed close to the sample surface. This presents evidence for the onset of a
Morin transition or another type of spin-reorientation phase transition wherein
the Fe3+ moments would acquire a c-axis component to their canting below a
critical temperature. The observation of this c-axis magnetization suggests
that there is a different ground state in this material than has been
previously expected and could be due to as yet unexplored intricacies of the
Dzyaloshinskii-Moriya interaction.
