Some embodiments include a magnetic tunnel junction device having a first magnetic electrode, a second magnetic electrode, and a tunnel insulator material between the first and second magnetic electrodes. A tungsten-containing material is directly against one of the magnetic electrodes. In some embodiments the tungsten-containing material may be in a first crystalline lattice arrangement, and the directly adjacent magnetic electrode may be in a second crystalline lattice arrangement different from said first crystalline lattice arrangement. In some embodiments the tungsten-containing material, the first magnetic electrode, the tunnel insulator material and the second magnetic electrode all comprise a common crystalline lattice arrangement.