  Antiferromagnetic (AF) materials are attracting increasing interest of
research in magnetic physics and spintronics. Here, we report controllable
synthesis of room-temperature AF $\alpha$-MnTe nanocrystals (N\'eel temperature
~ 307 K) via molten-salt-assisted chemical vapor deposition method. The growth
kinetics are investigated regarding the dependence of flake dimension and
macroscopic shape on growth time and temperature. The high crystalline quality
and atomic structure are confirmed by various crystallographic characterization
means. Cryogenic magneto-transport measurements reveal anisotropic
magnetoresistance (MR) response and a complicated dependence of MR on
temperature, owing to the subtle competition among multiple scattering
mechanisms of thermally excited magnetic disorders (magnon drag), magnetic
transition and thermally populated lattice phonons. Overall positive MR
behavior with twice transitions in magnitude is observed when out-of-plane
external magnetic field ($B$) is applied, while a transition from negative to
positive MR response is recorded when in-plane $B$ is applied. The rich
magnetic transport properties render $\alpha$-MnTe a promising material for
exploiting functional components in magnetic devices.
