Magnetotransport around the Morin transition in alpha-Fe2O3 single crystals

Antiferromagnetic spintronics has been receiving attention recently, while spin-texture dependent magnetoresistance (MR) represents one of the main mechanisms for magnetic data storage. In particular, sufficiently large MR with high operating temperatures would be highly required for advanced spintronic applications. In this work, we experimentally investigate the MR effect of well-known antiferromagnet alpha-Fe2O3 (hematite) in a single crystal form, which has the Morin transition temperature as high as T-m similar to 260 K. It is revealed that the MR effect associated with the spin-texture re-alignment, i.e., the spin-flop from the out-of-plane direction (c axis) to the in-plane direction, driven by sufficiently low magnetic fields inclined along the [012] direction, reaches up to similar to 2.5% at temperature T similar to 250 K. The first-principles calculations suggest that this MR effect originates from the reduced bandgap due to the spin-flop and the finite spin-orbital coupling. The present work sheds light on the possibility of alpha-Fe2O3 as a favored MR-based candidate for near-room temperature spintronics. Published under an exclusive license by AIP Publishing.