A ferromagnetic free layer, a preparation method and an application thereof are provided, where the ferromagnetic layer includes a magnetic film alloy, and the magnetic film alloy includes multiple layers of laminated films. A thickness of each of the films decreases gradually from a first end to a second end of the magnetic film alloy, so as to break in-plane structural symmetry of the magnetic film alloy, and the films include heavy metal films and ferromagnetic metal films, where out-of-plane crystal symmetry of the magnetic film alloy is broken by means of component gradients. When a current is applied in plane of the magnetic film alloy, a spin orbit torque will be generated, which directly drives the magnetic moment of the magnetic film alloy to undergo a deterministic magnetization reversal.

A magnetoresistance effect element includes first and second magnetic layers having a perpendicular magnetization direction, and a first non-magnetic layer disposed adjacent to the first magnetic layer and on a side opposite to a side on which the second magnetic layer is disposed. An interfacial perpendicular magnetic anisotropy exists at an interface between the first magnetic layer and the first non-magnetic layer, and the anisotropy causes the first magnetic layer to have a magnetization direction perpendicular to the surface if the layers. The second magnetic layer has a saturation magnetization lower than that of the first magnetic layer, and an interfacial magnetic anisotropy energy density (K.sub.i) at the interface between the first magnetic layer and the first non-magnetic layer is greater than that of an interface between the first non-magnetic layer and second magnetic layers if being disposed adjacent each other.

A method for forming a multilayer thin film exhibiting perpendicular magnetic anisotropy includes alternately sputtering a CoFeSiB target and a Pd target inside a vacuum chamber to form a [CoFeSiB/Pd] multilayer thin film on a substrate disposed inside the vacuum chamber. The number of times the [CoFeSiB/Pd] multilayer thin film is stacked may be 3 or more.

A method for forming a CoFeSiBPd alloy thin film exhibiting perpendicular magnetic anisotropy includes: simultaneously sputtering a CoFeSiB target and a Pd target inside a vacuum chamber to form a CoFeSiBPd alloy thin film on a substrate disposed inside the vacuum chamber; and annealing the substrate, on which the CoFeSiBPd alloy thin film is formed, to exhibit perpendicular magnetic anisotropy.

A non-collinear magnetoresistive device, includes: a free layer; a fixed layer; and a non-magnetic layer disposed between the free layer and the fixed layer, wherein the fixed layer has an easy magnetization direction in an in-plane direction or in a perpendicular direction, the free layer satisfies at room temperature expressions (1) and (2) below:

E.sub.RT?1.66?10.sup.?19 J(1)

V?5?10.sup.4 nm.sup.3(2)

where E.sub.RT=(K.sub.u1,eff+K.sub.u2+K.sub.u1,eff.sup.2/4K.sub.u2)?V, K.sub.u1,eff: an effective first-order anisotropy constant, K.sub.u2: a second-order anisotropy constant, and V: a volume, and wherein the free layer is in a cone magnetization state.

Perpendicular spin transfer torque memory (STTM) devices with enhanced stability and methods of fabricating perpendicular STTM devices with enhanced stability are described. For example, a material layer stack for a magnetic tunneling junction includes a fixed magnetic layer. A dielectric layer is disposed above the fixed magnetic layer. A free magnetic layer is disposed above the dielectric layer. A conductive oxide material layer is disposed on the free magnetic layer.

A laminating structure includes a first magnetic layer, a second magnetic layer, a first spacer disposed between the first and second magnetic layers and a second spacer disposed on the second magnetic layer.

A laminating structure includes a first magnetic layer, a second magnetic layer, a first spacer disposed between the first and second magnetic layers and a second spacer disposed on the second magnetic layer.

More stable perpendicular magnetization orientation is attained, and switching of the magnetization orientation between an out-of-plane direction and an in-plane direction is enabled by voltage. A multiferroic laminated structure having ferroelectricity and ferromagnetism includes: a ferroelectric layer made of a ferroelectric substance having the ferroelectricity; a foundation layer composed mainly of a metal having a good lattice-matching property with the ferroelectric substance and laminated on a surface of the ferroelectric layer; an intermediate layer composed mainly of a non-magnetic substance and laminated on a surface of the foundation layer; and a ferromagnetic/non-magnetic multilayer film layer constituted by alternately laminating ferromagnetic layers and non-magnetic layers on a surface of the intermediate layer in at least three cycles, the ferromagnetic layers being composed mainly of a ferromagnetic substance, the non-magnetic layers being composed mainly of the non-magnetic substance.

A seed layer stack with a smooth top surface having a peak to peak roughness of about 0.5 nm over a range of 100 nm is formed by sputter depositing an X layer such as Mo on a Ni layer where the X layer has one or both of a larger bond energy and a greater atomic number than Ni. A (Ni/X).sub.m laminate is formed and then an uppermost NiCr seed layer is deposited to enhance perpendicular magnetic anisotropy (PMA) in an overlying ferromagnetic layer. A <111> NiCr crystal structure promotes <111> texture in the ferromagnetic layer. X layers serve as a diffusion barrier to Ta migration from a bottom electrode and have good lattice matching with the adjoining Ni layer and uppermost NiCr layer. As a result of the smooth seed layer stack in a magnetic tunnel junction (MTJ), MTJ properties are improved and more reproducible.