  Crystal growth of MnBi$_{2}$Te$_{4}$ has delivered the first experimental
corroboration of the 3D antiferromagnetic topological insulator state. Our
present results confirm that the synthesis of MnBi$_{2}$Te$_{4}$ can be
scaled-up and strengthen it as a promising experimental platform for studies of
a crossover between magnetic ordering and non-trivial topology. High-quality
single crystals of MnBi$_{2}$Te$_{4}$ are grown by slow cooling within a narrow
range between the melting points of Bi$_{2}$Te$_{3}$ (586 {\deg}C) and
MnBi$_{2}$Te$_{4}$ (600 {\deg}C). Single crystal X-ray diffraction and electron
microscopy reveal ubiquitous antisite defects in both cation sites and,
possibly, Mn vacancies. Powders of MnBi$_{2}$Te$_{4}$ can be obtained at
subsolidus temperatures, and a complementary thermochemical study establishes a
limited high-temperature range of phase stability. Nevertheless, quenched
powders are stable at room temperature and exhibit long-range antiferromagnetic
ordering below 24 K. The expected Mn(II) out-of-plane magnetic state is
confirmed by the magnetization, X-ray photoemission, X-ray absorption and
linear dichroism data. MnBi$_{2}$Te$_{4}$ exhibits a metallic type of
resistivity in the range 4.5-300 K. The compound is an n-type conductor that
reaches a thermoelectric figure of merit up to ZT = 0.17. Angle-resolved
photoemission experiments provide evidence for a surface state forming a gapped
Dirac cone.
