In one embodiment, the magnetic memory device includes a free layer structure having a variable magnetization direction. The free layer structure includes a first free layer, the first free layer being a first Heusler alloy; a coupling layer on the first free layer, the coupling layer including a metal oxide layer; and a second free layer on the metal oxide layer, the second free layer being a second Heusler alloy, the second Heusler alloy being different from the first Heusler alloy.

Disclosed is an electric field-controlled magnetoresistive random-access memory (MRAM) including memory cells. The memory cell has a heterogenous double tunnel junction structure including a first tunnel junction and a second tunnel junction. The first tunnel junction includes a magnetic tunnel junction layer having a magnetization direction that changes according to spin transfer torque when an external voltage is applied, and the second tunnel junction includes an electric-field control layer that controls an electric field applied to the magnetic tunnel junction layer to induce a change in magnetic anisotropy within the magnetic tunnel junction layer. The heterogeneous tunnel junction structure combines electric field-controlled magnetic anisotropy and spin transfer torque to enable low power driving of memory cells, thereby enabling a high energy-efficient electric field-controlled MRAM.

An electronic device may include a semiconductor memory, and the semiconductor memory may include a substrate; a variable resistance element formed over the substrate and exhibiting different resistance values representing different digital information, the variable resistance element including a free layer having a variable magnetization direction, a pinned layer having a fixed magnetization direction and a tunnel barrier layer interposed between the free layer and the pinned layer; and a blocking layer disposed on at least sidewalls of the variable resistance element, wherein the blocking layer may include a layer that is substantially free of nitrogen, oxygen or a combination thereof.

Provided are a magnetic tunneling junction device having more stable perpendicular magnetic anisotropy (PMA) and/or increased operating speed, and/or a memory device including the magnetic tunneling junction device. The magnetic tunneling junction device includes a free layer having a first surface and a second surface opposite the first surface; a pinned layer facing the first surface of the free layer; a first oxide layer between the pinned layer and the free layer; and a second oxide layer on the second surface of the free layer. The free layer includes a magnetic material X doped with a non-magnetic metal/ The second oxide layer includes ZO.sub.x which is an oxide of a metal Z. An oxygen affinity of the metal Z is greater than an oxygen affinity of the non-magnetic metal X.

Provided are a magnetic tunneling junction device having a fast operating speed without reducing or with increasing data retention and/or a memory device including the magnetic tunneling junction device. The magnetic tunneling junction device includes a free layer having a first surface and a second surface opposite the first surface; a pinned layer facing the first surface of the free layer; a first oxide layer between the pinned layer and the free layer; and a second oxide layer on the second surface of the free layer. The free layer includes a first free layer adjacent to the first oxide layer and a second free layer adjacent to the second oxide layer. The first free layer includes a magnetic material not doped with a non-magnetic metal, and the second free layer includes a magnetic material doped with the non-magnetic metal.

A device is provided. The device includes a physical unclonable function (PUF) cell array. The PUF cell array includes multiple bit cells, and generates a PUF response output, in response to a challenge input, based on a data state of one bit cell in the bit cells. Each of the bit cells stores a bit data and includes a transistor having a control terminal coupled to a word line and a first terminal coupled to a source line, a first memory cell having a first terminal coupled to a first data line and a second terminal coupled to a second terminal of the transistor, and a second memory cell having a first terminal coupled to a second data line, different from the first data line, and a second terminal coupled to the second terminal of the first memory cell at the second terminal of the transistor.

A magnetoresistance effect element has a first ferromagnetic metal layer, a second ferromagnetic metal layer, and a tunnel barrier layer that is sandwiched between the first and second ferromagnetic metal layers, and the tunnel barrier layer has a spinel structure represented by a composition formula of AIn.sub.2O.sub.x (0<x≤4), and an A-site is a non-magnetic divalent cation which is one or more selected from a group consisting of magnesium, zinc and cadmium.

Provided are a magnetic tunneling junction device having a relatively high tunneling magnetoresistance (TMR) ratio; and a memory device including the magnetic tunneling junction device. The magnetic tunneling junction device includes: a pinned layer having a first surface and a second surface opposite the first surface; a seed layer disposed in contact with the first surface of the pinned layer; a free layer disposed to face the second surface of the pinned layer; and a tunnel barrier layer disposed between the pinned layer and the free layer, wherein the seed layer includes at least one amorphous material selected from CoFeX and CoFeXTa, and the X includes at least one element selected from niobium (Nb), molybdenum (Mo), tungsten (W), chromium (Cr), zirconium (Zr), and hafnium (Hf). The seed layer may not include boron.

A semiconductor memory structure includes bottom electrodes formed over a substrate. The structure also includes first magnetic tunneling junction (MTJ) elements formed over the bottom electrodes in a first region and a second region of the substrate. The structure also includes second MTJ elements formed over the first MTJ elements in the first region and the second region. The structure also includes top electrodes formed over the second MTJ elements. The first MTJ elements in the first region are narrower than the second MTJ elements in the first region, and the second MTJ elements in the second region are narrower than the first MTJ elements in the second region.

Provided are a function switchable random access memory, including: two electromagnetic portions configured to connect a current; a magnetic recording portion between the two electromagnetic portions and including a spin-orbit coupling layer and a magnetic tunnel junction; a pinning region between each of the electromagnetic portions and the magnetic recording portion; a cut-off region on a side of each of the electromagnetic portions opposite to the pinning region, the spin-orbit coupling layer is configured to generate a spin current under an action of the current; the two electromagnetic portions is configured to generate two magnetic domains with magnetization pointing in opposite directions under an action of the spin current; the magnetic tunnel junction is configured to generate a magnetic domain wall based on the two opposite magnetic domains and is configured to drive the magnetic domain wall to reciprocate under the action of the spin current.