  Hematite at room temperature is a weak ferromagnetic material. Its permanent
magnetization is three orders smaller than for magnetite. Thus, hematite
colloids allow us to explore a different physical range of particle interaction
parameters compared to ordinary ferromagnetic particle colloids. In this paper
we investigate a colloid consisting of hematite particles with cubic shape. We
search for energetically favorable structures in an external magnetic field
with analytical and numerical methods and molecular dynamics simulations and
analyze whether it is possible to observe them in experiments. We find that
energetically favorable configurations are observable only for short chains.
Longer chains usually contain kinks which are formed in the process of chain
formation due to the interplay of energy and thermal fluctuations as an
individual cube can be in one of two alignments with an equal probability.
