Magnetic tunnel junctions with perpendicular magnetization and magnetic random access memory

A magnetic tunnel junction, comprising:

• a reference layer whose magnetization direction is invariable;
• a recording layer whose magnetization direction is variable;
• and
• a nonmagnetic layer electrically connected between the reference layer and the recording layer,
• wherein
• magnetization of the reference layer and the recording layer is perpendicular to a film plane,
• the reference layer and the recording layer include a current supply terminal,
• the reference layer is larger in area than the recording layer,
• a thermal stability factor of the magnetic tunnel junction satisfies the relationship:
• EAP/kBT=E0(1−Hs/Hkrec)2/kBT≧40, and
• a magnitude of a dipole coupling magnetic field generated from the reference layer at a center of the recording layer satisfies the relationship:
• Hs=Mstref(dref/2)2/2μ0[{(dref/2)2+tbar2}3/2],
• where EAP represents an energy barrier when magnetization of the reference layer and magnetization of the recording layer are placed in anti-parallel to each other, kB represents a Boltzmann's constant, T represents absolute temperature, E0 represents an energy barrier without dipole coupling, Hkrec represents an anisotropy magnetic field of the recording layer, dref represents a diameter of a circle whose area is identical to the area of the reference layer, tref represents a film thickness of the reference layer, tbar represents a film thickness of the nonmagnetic layer, and μ0 represents a magnetic permeability under vacuum.