Properties of sputtered full Heusler alloy Cr₂MnSb and its application in a magnetic tunnel junction

We deposit 30 nm thick Cr₂MnSb films on a MgO(0 0 1) substrate by magnetron sputtering. X-ray diffraction reveals that the annealing promotes the crystallization of Cr₂MnSb from amorphous at as-deposited state to partially crystallized phase, and that the crystallinity improves by raising the annealing temperature. The crystallized phase exhibits full B2 and partial L2₁ ordering after the annealing above 300 °C. The magnetic and magneto-transport properties reveal that the annealed Cr₂MnSb shows magnetic ordering up to ∼350 K with small magnetic moment, 0.3µ _B/formula unit for the sample annealed at 300 °C. We adopt Cr₂MnSb as one of the electrodes in magnetic tunnel junctions (MTJs), and observe the switching of junction resistance, when the magnetization direction is reversed by sweeping an external magnetic field.