In the OSTI Collections: Spintronics

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Article Acknowledgement:
Dr. William N. Watson, Physicist
DOE Office of Scientific and Technical Information

 

Experiment

Theory

Invention

Prospects

References

Reports available through SciTech

Reports available through DOE PAGESBeta

Reports available through DOepatents

Additional references

 

 

Electric current—the flow of electric charge—has been the basis of electromagnetic devices from the 18th century onwards.  A device’s electromagnetic field will be much the same whether positive charges flow forward through the device at a particular rate or negative charges flow backward along the same path at the same rate.  Any motion of positive and negative particles that yields the same overall transfer of charge produces much the same electromagnetic effect. 

 

But all of the apparently simplest charged particles turn out to be magnets as well, whose north and south poles are oriented in some definite way along any given direction.  And just as one can establish a flow of electric charge, one can also set up a flow of magnetic orientation.  Such a flow can consist, for example, of either upward-pointing magnetic north poles flowing to the right or upward-pointing magnetic south poles flowing to the left; the electromagnetic effects are much the same either way.  Yet none of the earliest electromagnetic devices were based on the flow of particles’ magnetic orientation.  For one thing, the magnetism of elementary charged particles was unknown until the 20th century—indeed, the existence of elementary charged particles wasn’t known until the late 19th century.[Wikipedia] 

 

Since a charged particle’s magnetic orientation is closely associated with its intrinsic angular momentum, or “spin”, electronics based on the flow of magnetic orientation has been named “spintronics”.[Wikipedia]  The Department of Energy has sponsored much research to advance spintronics along several fronts, as exemplified by several recent reports. 

 

Experiment

 

At Texas Tech University, a “Single Individual and Small Group Research” (“SISGR”) grant supported a study of magnetism in several semiconductors that have been suggested as candidate spintronic materials.  The technique used involved examining how the magnetic fields of the particles composing a semiconductor affected the orientation of certain electronlike magnetic particles (muons[Wikipedia]) sent into the semiconductor.  Muons’ electric charges are the same size as electrons’, but their masses are almost 207 times as great.  Since they generally decay into other particles rapidly, with an average decay time of just under 2.2 microseconds (or a half-life of about 1.5 microseconds), their orientations aren’t always directly measurable; instead, the likelihood of any particular orientation is determined by measuring the orientation of the muons’ more stable decay products, particularly the electron or positron produced when a negative or positive muon decays. 

 

The Texas Tech project focused on characterizing entities in these experiments known as spin polarons[SciTech Connect]—combinations of particle spins in which one mobile particle’s magnetism reorients any magnetic particles near it into the opposite direction as it passes by.  A muon implanted in a semiconductor can form a spin polaron by inducing reorientation of the semiconductor’s own magnetic particles, or it can interact with spin polarons already formed around some of the semiconductor’s own mobile electrons.  In the course of the project, small spin polarons were observed in over 50 separate materials by the technique of muon spin resonance (MuSR, or ?SR)[Wikipedia].  The project report, “SISGR-MuSR Investigations of Magnetic Semiconductors for Spintronics Applications”[SciTech Connect], lists some important findings about several types of materials, including: 

  • ferromagnetic compounds of the element europium with chalcogenides[Wikipedia],
  • the semiconductor CdCr2Se4,
  • the parent compounds of high-Tc cuprate superconductors[Wikipedia; Wikipedia],
  • manganese silicide,
  • NaV2O5,
  • uranium germanide,
  • Cd2Re2O7,
  • several materials like Lu2V2O7 that exhibit colossal magnetoresistance[Wikipedia],
  • FeGa3,
  • FeSb2,
  • UBe13 and other materials in which superconductivity and antiferromagnetism[Wikipedia] coexist, and
  • ZnGeP2 doped with manganese. 

The report also lists 12 refereed published papers, each focused on what was learned from experiments with one material or type of material. 

 

 

Figure 1.  Spin polarons are produced in a material when one particle’s magnetism affects the orientations of nearby particles so that their magnetic fields are in the opposite direction.  The particles’ magnetic fields are tied to their spin orientations.  The combination of the interacting particles’ spin orientations constitutes a spin polaron.  Spin polarons are analogous to ionic polarons, which form when a charged particle attracts oppositely charged particles and repels identically charged particles.  In both cases, one particle’s electromagnetic field rearranges the positions or orientations of other particles.  This figure, a schematic illustration of (a) ionic polarons and (b) spin polarons, is taken from a report for the 1993 International Symposium on High-Tc Superconductivity and Its Applications in Cairo, “Spin-polaron theory of high-Tc superconductivity I.  Spin polarons and high-Tc pairing”[SciTech Connect].

 

A different group of researchers working at three different institutions (the University of Pittsburgh, the University of California, Santa Barbara, and the University of Virginia) explored the fabrication of materials suitable for spintronic devices whose possible electron states would span different ranges (or bands) of possible energies, with a gap between the bands.  Their report, “Development of Spintronic Bandgap Materials”[SciTech Connect], describes how they determined the conditions for the self-assembly of arrays of nanometer-scale semiconductors, or “quantum dots”[Wikipedia], with the dots positioned to a precision of 2 nanometers and spaced as little as 22 nanometers apart.  The arrays were measured to learn the widths of their electron distributions, determine how the strength of electrical forces between quantum dots depends on their spacing, and see how electric currents within them varied with the voltages and magnetic fields applied to them. 

 

Measurement of single electron spins in a quantum dot was also desired, but constructing germanium quantum dots in which this is possible was itself a challenge, since the means chosen was to dope the dots with individual ions of manganese.  The problem here was that manganese is barely soluble in solid germanium.  Even one manganese ion in a dot of some 10,000 to 100,000 germanium atoms is enough to oversaturate the germanium; the equilibrium manganese/germanium ratio at room temperature is less than 1/1,000,000.  But to grow self-assembling quantum dots of germanium, layers of germanium atoms need to be deposited at even higher temperatures.  All this makes it impossible to get the manganese atoms into the germanium dots by dissolving them in.  The researchers got around this problem by first depositing germanium quantum dots under standard growth conditions, then cooling them to under 100°C and flashing on a coverage of around 100,000,000,000 manganese ions per square centimeter (or about 1 ion for every 10,000 germanium atoms at a dot’s surface), and then encapsulating the manganese by growing an additional single layer of germanium atoms at low temperature. 

 

The data from all the different measurements on the quantum dots can be used to work out how to manipulate states of electron charge and spin in quantum-dot based spintronic devices.  Six papers describing results from the DoE-supported research are cited in the project report. 

 

Many materials’ electric and magnetic properties are very dependent on the conditions the materials are exposed to.  Other properties, like the permanent magnetism of iron and other materials (ferromagnetism), can remain even when the conditions that induced them are removed.  Analogously to this magnetic property, spontaneous electric polarization and strain in a material are respectively named ferroelectricity and ferroelasticity.  Materials exhibiting more than one such property are called multiferroics.[Wikipedia]  Few materials are both ferromagnetic and ferroelectric, since most ferromagnetic materials conduct electric current while most ferroelectric materials are insulators. 

 

One report published in 2014 in the journal Advanced Functional Materials noted that, while no materials were known to be both ferromagnetic and ferroelectric at room temperature, BiFe0.5Mn0.5O3 might prove to be such a material if strain were built into it, based on experiments exploring the properties of similar materials.  The report, “Room temperature ferrimagnetism and ferroelectricity in strained, thin films of BiFe0.5Mn0.5O3”[DoE PAGES], describes experiments in which the material was prepared and its properties measured.  The report’s title indicates what the researchers were trying to achieve; their actual result was to demonstrate the material’s multiferroism at temperatures high above absolute zero (around 600 kelvins, or twice room temperature).  The report notes that demonstrating this “is a promising development for future spintronic and memory applications at room temperature and above” such as devices that can filter the flow of particles with a given spin orientation, new four-state memory devices (as opposed to the two-state, 1-and-0 based memories of today’s devices), and other tunable multifunctional devices based on spin flow. 

 

Electron spins can be reoriented by changes in the direction of the ambient magnetic field.  Thus, if the magnetic field of a conductor were set up to vary from one atom to the next in a particular way, any electrons passing through the conductor would be reoriented as they traveled.  This would mean that the associated spin current could be controllably altered.  Controlling the variation in conductors’ magnetic fields is the goal of work described in the Scientific Reports paper “Manipulating topological states by imprinting non-collinear spin textures”[DoE PAGES].  The authors note that, with current nanometer-scale fabrication methods, any of a variety of stable magnetic-field patterns can be built into layered structures of conventional magnetic materials.  They demonstrated their method of controlling and manipulating the patterns by observing the magnetic configurations and magnetization reversal processes in films of cobalt[Wikipedia] and palladium[Wikipedia] separated by thin, nonmagnetic palladium spacers from suitably magnetized layers of Permalloy[Wikipedia].  While the magnetization patterns were switched back and forth by applying magnetic fields, the authors state that this approach can be further extended to current-driven switching as required for future spintronic devices. 

 

 

Figure 2.  (a) Illustration of how the spin orientations of particles in a cobalt-palladium layer, whose associated magnetic fields are originally aligned perpendicular to the layer (“out-of-plane”), can be imprinted with new orientations by stacking layers of differently oriented particles onto them.  Py:  Permalloy (nickel-iron—Ni80Fe20) [Wikipedia]; cobalt (Co)[Wikipedia]; palladium (Pd)[Wikipedia].  (b)-(e) Magnetic configurations of four different states in Co/Pd films whose magnetic couplings Ji with the Py layer vary from stronger (b) to weaker (e).  (f) The opening angle of states like those shown in (c) and (d) might be tailored by adjusting the interlayer magnetic coupling Ji.  Mz/Ms represents magnetization out of the plane of the Co/Pd layer; x is distance in nanometers from the center of the pattern. (From “Manipulating topological states by imprinting non-collinear spin textures”[DoE PAGES].) 

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Theory

 

While the quite stable magnetization patterns observed in these experiments could be used to change the spin orientations of magnetic particles passing through them, if the patterns themselves can move around, they can function like particles.  The mathematical description of these particle-like patterns of atoms’ magnetic-field and spin orientation puts them in a class of entities known as skyrmions[Wikipedia], which are named after physicist Tony Skyrme[Wikipedia], who first examined nonmagnetic particle-like entities with a similar mathematical description in nuclear physics.  Hence the title of a paper published by Los Alamos National Laboratory scientists in New Journal of Physics, “Magnus-induced ratchet effects for skyrmions interacting with asymmetric substrates”[DoE PAGES]. 

 

The paper describes a theoretical calculation of how magnetic skyrmions would move around, in response to applied forces, within an asymmetric layer of material through which they can easily be accelerated forward but not backward along a particular axis.  Because the magnetic fields of electrons in the skyrmions also have an asymmetry, being oriented either clockwise or counterclockwise as shown in Figure A, their acceleration in response to an applied force is not in the same direction as the force, but at some angle to it—a phenomenon much like the Magnus effect[Wikipedia] seen when a spinning projectile (such as a pitched baseball) is deflected from its forward track when plowing through the air or another fluid.  And because of the asymmetry in the material layer that the skyrmions travel over, an applied alternating force moves the skyrmions further in one direction than in the opposite direction along the material’s asymmetry axis—the ratcheting effect referred to in the paper’s title.  The motions are quite different according to whether the alternating force is along the material’s asymmetry axis or perpendicular to it, as shown in Figure 3.  “Such ratchet effects,” say the paper’s authors, “offer a new method for controlling skyrmion motion that could be harnessed in skyrmion applications.”  They also expect that “skyrmions could exhibit a rich variety of other ratchet behaviors under different conditions”, such as more complicated material geometries, asymmetric alternating applied forces, or collective effects from skyrmion interactions. 

 

 

Figure 3. Upper left:  A schematic of a skyrmion (red dot) placed on an asymmetric substrate.  An alternating-current driving force is applied parallel () or perpendicular () to the asymmetry direction.  Upper right:  Motions of the skyrmion for alternating forces parallel to the asymmetry direction, given different degrees of influence from damping, viscosity-like forces and from deflecting forces like those of the Magnus effect.  Thin lines represent forward trajectories, thicker lines represent backtracking.  Bottom:  Skyrmion motions with other variations in viscosity-like and Magnus-like effects, but driven by alternating forces perpendicular to the substrate’s asymmetry direction.  (From “Magnus-induced ratchet effects for skyrmions interacting with asymmetric substrates”[DoE PAGES].) 

 

The behavior of spin currents in single layers of atoms have been calculated for different materials.  Many calculations have been made for the simplest possible such materials:  those consisting only of one layer of atoms, with no other atoms near it.  But in at least some real materials, the single current-conducting layer is likely to be supported by a bulk material of different atomic composition, which would affect the current.  One set of calculations apiece for each type of material is described in each of two papers, both published in Scientific Reports.   The atom layers described in these papers could be formed by starting with layers that consist of one element only, and replacing some of the atoms with atoms of a different element. 

 

The paper by researchers at James Madison University, Los Alamos National Laboratory, and NORDITA, “Proximity-induced magnetism in transition-metal substituted graphene”[DoE PAGES], describes a single, rhombus-shaped layer of 128 atoms unsupported by a bulk substrate.  The layer is mostly graphene[Wikipedia, OSTI], with two of the carbon atoms near the center of the graphene layer replaced by light metal atoms of the same element—either manganese[Wikipedia], chromium[Wikipedia], vanadium[Wikipedia], or titanium[Wikipedia].  The researchers made extensive calculations of the effect of the metal atoms, particularly how the metal atoms’ presence induces magnetism in the otherwise nonmagnetic graphene.  The effects differ according to which element substitutes for the two carbon atoms, and whether the replacing atoms are separated by one, two , three, four, five, or six carbon atoms (see Figure 4).  The carbon atoms near the metal atoms “gain a distinct magnetic moment” and “produce a complex network of exchange interactions”.   The report concludes:  “The presence of variable magnetic exchange due to in-situ substitution and induced magnetism in graphene shows the increased possibility of using graphene for spintronic materials.  These calculations are meant as the motivation for the use for magnetically-doped graphene and other 2D materials for the possible advancement for spintronic devices and quantum computation”—the latter possibility offering the rapid solution of problems that present-day computers are inherently too slow to solve[OSTI]. 

 

 

Figure 4.  The paper “Proximity-induced magnetism in transition-metal substituted graphene”[DoE PAGES] presents analyses of the effects of substituting atoms of a light metal for two of the carbon atoms in the middle of a 128-atom graphene sheet.  (a) Analyses are made for sheets in which the light-metal atoms are separated by N carbon atoms, N being any number from 1 to 6.  (b) and (c)  Views of how the substituted atoms distort the graphene structure when the substituted atoms are separated by one and six carbon atoms, respectively. 

 

One can think of the bulk-supported layer analyzed by researchers at the University of Utah, the Beijing Institute of Technology, and Beijing’s Collaborative Innovation Center of Quantum Matter as one in which a lot more replacements are made in a monolayer of hydrogen.  In this case, though, the hydrogen atoms aren’t bonded to each other like the carbon atoms of a graphene sheet, but to silicon atoms at the surface of a bulk silicon substrate; the replacing atoms are of a heavy metal like bismuth[Wikipedia] or lead[Wikipedia] instead of a light metal; and instead of replacing only two of the hydrogens, the metal atoms replace two-thirds of the hydrogens.  While the heavy elements’ electrons show strong coupling between their spin-related magnetic fields and the magnetic fields associated with their orbital motions, these orbital motions would be shaped by the silicon substrate.  The researchers’ paper, “Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling”[DoE PAGES], examines the kind of surfaces depicted in Figure 5, and demonstrates that their analysis method could be used to design combinations of metals and substrates in which spin currents could flow. 

 

 

Figure 5.  Construction of a bulk-supported two-dimensional spintronic material (schematic view).  Hydrogen atoms are first selectively removed from an underlying bulk sample of silicon by a scanning tunneling microscope[Wikipedia], which can be used to manipulate atoms as well as to view them.  Next, the removed hydrogen atoms are replaced by atoms of a heavy metal like bismuth or lead.  (From “Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling”[DoE PAGES].) 

 

An ideal spintronic material would be a half-metal[Wikipedia]:  it would conduct electrons with one spin-orientation as a metal would, while blocking the motion of oppositely-oriented electrons as an insulator would.  Around 2005, several research groups began to explore candidate spintronic materials based on silicon.  A book by researchers at the University of California, Davis and Lawrence Livermore National Laboratory, entitled “Recent Progress in Silicon-based Spintronic Materials”[SciTech Connect], describes calculation methods for designing new spintronic materials so that materials with the most favorable properties can be selected for production.  The book, Volume 1 for a series on spintronics by the publisher World Scientific, begins with features of solid materials related to their electrons’ interactions with each other and with external electromagnetic fields—keys to designing materials with desirable spintronic properties.  Next, the book presents methods commonly used in spintronic-material design for calculating what these interactions are and the temperature above which a material’s magnetization is lost[Wikipedia], as well as methods for growing crystalline materials and characterizing their properties.  The last chapter presents recent progress in developing silicon-based spintronic materials, emphasizing an understanding of their physical mechanisms and the terms used to describe them. 

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Invention

 

While spintronic devices have used currents in which more electron spins are oriented one way than the opposite way, currents with all the spins oriented one way “would be even better for spintronics” in the words of a patent assigned to the Johns Hopkins University in 2014.  However, according to the patent (“Ferromagnets as pure spin current generators and detectors”[DOepatents]), only a few electrical mechanisms generate pure spin currents from charge currents, or detect pure spin currents by converting them to charge currents; accordingly, spintronics devices “such as spin current generators and detectors” are needed “that offer higher spin and charge conversion efficiency and much lower cost”.  The patent goes on to describe such devices, which involve a magnetic dielectric layer sandwiched between a substrate and a ferromagnetic metal layer.  The dielectric layer’s magnetic moment is controlled by a magnetic field and the metal layer is in contact with positive and negative electrodes.  Depending on whether the electrodes are connected to a voltmeter or a current source, either the dielectric or the metal layer respectively will function as a spin-current generator, in which case the other layer will function as a spin-current detector.  The dielectric layer will generate particles with a particular spin if it’s exposed to a source of microwaves whose frequency is the dielectric’s resonance frequency. 

 

Another patent, assigned to the University of Utah Research Foundation, describes “Organic spintronic devices and methods for making the same”[DOepatents].  These address a different problem.  Solar cells made of inorganic crystals turn a large fraction of the energy from incident light into electrical energy, but are difficult and expensive to manufacture, while solar cells made of organic materials are much easier and cheaper to produce, are flexible, and can be made in different colors, but they generate electrical energy from light energy much less efficiently.  The energy converted by a solar cell goes into energizing electrons out of less mobile states so that they can move freely through the cell in response to electric fields.  Each electron so energized leaves a “hole” in the state it once had among the remaining non-energized electrons.  Each hole also acts like a moving positive charge, as one remaining negative electron after another changes its state in response to the same electric fields to occupy whatever electron state is currently vacant—not unlike the way a bubble in a fluid, a vacancy among the fluid’s molecules, acts like a moving object itself.  In ordinary solar cells, neither a moving “hole” nor an energized electron will last long.  The energized electrons tend to lose energy very quickly, and their mobilities, as well as the mobilities of the holes, are too low for the holes and the energized electrons to separate very much before the electrons lose their extra energy.  When they do lose this energy, the electrons occupy nearby “holes”, becoming less mobile again and making the holes disappear.  By combining with each other in this way, both the “holes” and the previously energized electrons cease to provide flows of positive and negative charge.  This process appears to be among the main contributors to the inefficiency of ordinary solar cells.  The patented invention addresses this problem by including molecular radicals[Wikipedia] or other materials that induce energized electrons or holes to flip their spin orientations, putting them into states from which they’ll less readily combine and stop carrying electric charge.  This device thus produces an ordinary charge current, but has a spintronic feature that lets it produce that current with less light. 

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Prospects

 

A review article in Physical Review Applied by researchers at Argonne National Laboratory presents their personal view of some recent developments in spintronics “to stimulate interest in the great variety of directions the field is taking” which, according to the authors, “is a healthy sign for a maturing field”.  “Opportunities at the Frontiers of Spintronics”[DoE PAGES]” describes examples that illustrate four topics: 

 

  • the production and detection of spin currents in materials—even nonmagnetic materials;
  • the interplay of spin and charge currents with heat currents;
  • couplings of spins with each other, which are important for understanding how spin, charge, and heat currents interact;
  • couplings of spins with electromagnetic waves (photons). 

 

The article emphasizes the potential of spintronics in information technology: 

 

While the initial applied impact of spintronics is mostly related to information storage, which already utilizes magnetic materials for long-term data retention, more recently, there have been increased efforts to integrate spintronic concepts also into the logic operations of information technologies.  The driver for combining spintronics with semiconducting logic is that the continuous miniaturization of semiconducting electronics known as “Moore’s law”[Wikipedia] goes hand in hand with increased power dissipation due to leakage currents.  Towards this end, information-processing systems based on magnetic degrees of freedom offer appealing opportunities.  Unlike purely charge-based systems, information encoded in magnetization states is generally nonvolatile, thus, reducing the power requirement for maintaining data.  However, we note that with decreasing size, thermal stability (and, thus, volatility) becomes an issue that may require materials with increased magnetic anisotropies in order to develop magnetic devices with ultrahigh miniaturization.  Nevertheless, since the energy difference between opposite magnetization directions can be negligibly small, this offers, in principle, the possibility to manipulate data at its thermodynamic limits[Wikipedia].  Besides overcoming the power-dissipation limitations of semiconducting electronics, improved energy-efficient information technologies are also imperative for overcoming the concomitant increasing global energy consumption, which is driven, in part, by the ubiquitous growth in the popularity of electronic devices.

 

The authors use “provocative subtitles” to introduce the article sections on each of their four topics to suggest the topics’ applied aspects and opportunities for further research:  “spin orbitronics”, “spin caloritronics”, “magnonics”, and “ultrafast spin photonics”.   The association of the third topic, spin-spin couplings, with “magnonics”[Wikipedia] is that particle spins, coupled together, can result in particles’ magnetic-field orientations propagating from one particle to the next in the form of a wave (a “magnon”[Wikipedia]).  And dynamics that go beyond the frequencies of typical magnons is what “ultrafast spin photonics” refers to in connection with spin-photon couplings. 

 

In their article’s final section, the authors ask: 

 

Will these ideas enter the commercial arena and advance the field of information technology?  This question is of particular interest to ponder, given that the present year, 2015, represents the 50th anniversary of the famous prediction by Moore known as “Moore’s law”.  Moore extrapolated into the future the rise in the packing density of transistors on a chip.  Moore’s visionary prediction has since been loosely generalized to cover additional advances in the realm of information technology encompassing the mantra:  smaller, faster, cheaper, cooler.  However, the miniaturization of today’s silicon technology is leading to thermal problems.  This is where fields like spintronics can help, because they can involve less heat dissipation. Thus, we envision the possibility that spintronics can provide small and cool information-processing and storage systems in the future. We also see that the fast part looks promising within the spintronics realm.  Since economics tends to dominate the marketplace, it remains to be seen if and which emerging ideas will ultimately be cost effective to manufacture.  The playing field is wide open to explore.

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References

 

Wikipedia

 

 

Scientific Journals

 

 

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Reports available through OSTI’s SciTech Connect with the authors’ research organizations: 

 

“Spin-polaron theory of high-Tc superconductivity I.  Spin polarons and high-Tc pairing” [Metadata]

Invited paper for the International Symposium on High-Tc Superconductivity and Its Applications, Cairo (Egypt), 4-16 Apr 1993. 

 

“SISGR-MuSR Investigations of Magnetic Semiconductors for Spintronics Applications” [Metadata]

 

“Development of Spintronic Bandgap Materials” [Metadata]

 

“Recent Progress in Silicon-based Spintronic Materials” [Metadata]

Recent Progress in Silicon-based Spintronic Materials, World Scientific Publishing, Singapore, 2015, pp. 164

 

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Reports available through DoE PAGESBeta with the authors’ research organizations: 

 

“Room temperature ferrimagnetism and ferroelectricity in strained, thin films of BiFe0.5Mn0.5O3” [Metadata]

Advanced Functional Materials  Journal Volume: 24; Journal Issue: 47; Journal ID: ISSN 1616-301X

 

“Manipulating topological states by imprinting non-collinear spin textures” [Metadata]

Scientific Reports  Journal Volume: 5; Journal Issue: 1; Journal ID: ISSN 2045-2322

 

“Magnus-induced ratchet effects for skyrmions interacting with asymmetric substrates” [Metadata]

New Journal of Physics  Journal Volume: 17; Journal Issue: 7; Journal ID: ISSN 1367-2630

 

“Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling” [Metadata]

Scientific Reports  Journal Volume: 4; Journal ID: ISSN 2045-2322

 

“Proximity-induced magnetism in transition-metal substituted graphene” [Metadata]

Scientific Reports  Journal Volume: 5; Journal ID: ISSN 2045-2322

 

“Opportunities at the Frontiers of Spintronics” [Metadata]

Physical Review Applied  Journal Volume: 4; Journal Issue: 4; Journal ID: ISSN 2331-7019

(This article, published October 5, 2015, will become publicly available through DoE PAGES on October 4, 2016.)

 

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Reports available through DOepatents with the assignee organizations: 

 

“Ferromagnets as pure spin current generators and detectors” [Metadata]

 

“Organic spintronic devices and methods for making the same” [Metadata]

 

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Additional references

 

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Last updated on Wednesday 27 July 2016