Magnetoresistive device

A magnetoresistive device, including a free layer, a fixed layer, and a non-magnetic layer disposed between the free layer and the fixed layer, wherein:

• the free layer has an easy magnetization direction in a perpendicular direction or in an in-plane direction;
• in the case where the easy magnetization direction of the free layer is in the perpendicular direction, the fixed layer has the easy magnetization direction in the perpendicular direction, whereas, in the case where the easy magnetization direction of the free layer is in the in-plane direction, the fixed layer has the easy magnetization direction in the in-plane direction;
• and
• Ku1,eff is assumed to be an effective first order anisotropy constant, Ku2 is assumed to be a second order anisotropy constant, and rK is assumed to be Ku2/Ku1,eff, then, when a bias current flowing in the free layer is in vicinity of zero, the free layer satisfies both expression (1) and expression (2) below, or satisfies both expression (3) and expression (4) below:
• Ku1,eff>0 (1)
• rK≥0.1 (2)
• Ku1,eff=0 (3)
• Ku2>0 (4),