Perpendicular shape anisotropy design with asymmetric composite free layer

A memory device, comprising:

• a magnetic tunnel junction (MTJ) structure comprising perpendicular shape anisotropy, and the MTJ structure further comprising:
• a reference layer comprising a first side and a second side that is opposite the first side of the reference layer;
• a non-magnetic spacer comprising a first side and a second side, the first side of the non-magnetic spacer being on the second side of the reference layer and the second side of the non-magnetic spacer being opposite the first side of the non-magnetic spacer;
• and
• free layer comprising a first side and a second side, the first side of the free layer being on the second side of the non-magnetic spacer and the second side of the free layer being opposite the first side of the free layer, the free layer further comprising a first layer on the first side of the free layer, a second layer on the second side of the free layer and a coupling layer disposed between the first layer and the second layer, a ratio of thickness of the first layer to a thickness of the first layer and the second layer is less than 0.5, wherein a ratio of a thickness of the free layer to an in-plane lateral dimension of the MTJ structure ranges between a first value and a second value.

A memory device, comprising:

• a magnetic tunnel junction (MTJ) structure comprising perpendicular shape anisotropy, and the MTJ structure further comprising:
• a reference layer comprising a first side and a second side that is opposite the first side of the reference layer;
• a non-magnetic spacer comprising a first side and a second side, the first side of the non-magnetic spacer being on the second side of the reference layer and the second side of the non-magnetic spacer being opposite the first side of the non-magnetic spacer, the non-magnetic spacer comprising a metallic spacer;
• and
• a free layer comprising a first side and a second side, the first side of the free layer being on the second side of the non-magnetic spacer and the second side of the free layer being opposite the first side of the free layer, the free layer further comprising a first layer on the first side of the free layer, a second layer on the second side of the free layer and a coupling layer disposed between the first layer and the second layer, one of the first layer or the second layer comprises a Heusler material, and a saturation magnetization MsFL2 of the second layer being between 2 and 5 times inclusive of a saturation magnetization MsFL1 of the first layer.