  While in most ferro or antiferromagnetic materials there is a unique
crystallographic direction, including crystallographically equivalent
directions, in which the moments like to point due to spin-orbit coupling, in
some, the direction of the spin reorients as a function of a certain physical
parameter such as temperature, pressure etc. Fe3Sn2 is a kagome ferromagnet
with an onset of ferromagnetism below 650 K, and undergoes a spin reorientation
near 150 K. While it is known that the moments in Fe3Sn2 point perpendicular to
the kagome plane at high temperatures and parallel to the kagome plane at low
temperatures, how the distribution of the magnetic domains in the two different
spin orientations evolve throughout the spin reorientation is not well known.
Furthermore, while there have been various reports on the magnetotransport
properties in the Hall configuration, the angular dependence of
magnetoresistance has not been studied so far. In this paper, we have examined
the spin reorientation by using anisotropic magnetoresistivity in detail,
exploiting the dependence of the resistivity on the direction between
magnetization and applied current. We are able to determine the distribution of
the magnetic domains as a function of temperature between 360 K to 2 K and the
reorientation transition to peak at 120 K. We discover that both out of plane
and in plane phases coexist at temperatures around the spin reorientation,
indicative of a first order transition. Although the volume of the magnetic
domains in the different phases sharply changes at the spin reorientation
transition, the electronic structure for a specific magnetization is not
influenced by the spin reorientation. In contrast, we observe an electronic
transition around 40 K, hitherto unreported, and reflected in both the
zero-field resistivity and anisotropic resistivity.
