A New Kind of Magnetism Formed by “Magnetic Graphene” – Could Reveal Secrets of Superconductivity

Magnetism Concept

Researchers have identified a new form of magnetism in so-called magnetic graphene, which could point the way toward understanding superconductivity in this unusual type of material.

The researchers, led by the University of Cambridge, were able to control the conductivity and magnetism of iron thiophosphate (FePS3), a two-dimensional material that undergoes a transition from an insulator to a metal when compressed. This class of magnetic materials offers new routes to understanding the physics of new magnetic states and superconductivity.

Using new high-pressure techniques, the researchers have shown what happens to magnetic graphene during the transition from insulator to conductor and into its unconventional metallic state, realized only under ultra-high pressure conditions. When the material becomes metallic, it remains magnetic, which is contrary to previous results and provides clues as to how the electrical conduction in the metallic phase works. The newly discovered high-pressure magnetic phase likely forms a precursor to superconductivity so understanding its mechanisms is vital.

Their results, published in the journal Physical Review X, also suggest a way that new materials could be engineered to have combined conduction and magnetic properties, which could be useful in the development of new technologies such as spintronics, which could transform the way in which computers process information.

Magnetic Graphene Structure

Illustration of the magnetic structure of iron thiophosphate (FePS3), a two-dimensional material which undergoes a transition from an insulator to a metal when compressed. Credit: University of Cambridge

Properties of matter can alter dramatically with changing dimensionality. For example, graphene, carbon nanotubes, graphite, and diamond are all made of carbon atoms, but have very different properties due to their different structure and dimensionality.

“But imagine if you were also able to change all of these properties by adding magnetism,” said first author Dr Matthew Coak, who is jointly based at Cambridge’s Cavendish Laboratory and the University of Warwick. “A material which could be mechanically flexible and form a new kind of circuit to store information and perform computation. This is why these materials are so interesting, and because they drastically change their properties when put under pressure so we can control their behaviour.”

In a previous study by Sebastian Haines of the Cavendish Laboratory and the Department of Earth Sciences, researchers established that the material becomes a metal at high pressure, and outlined how the crystal structure and arrangement of atoms in the layers of this 2D material change through the transition.

“The missing piece has remained however, the magnetism,” said Coak. “With no experimental techniques able to probe the signatures of magnetism in this material at pressures this high, our international team had to develop and test our own new techniques to make it possible.”

The researchers used new techniques to measure the magnetic structure up to record-breaking high pressures, using specially designed diamond anvils and neutrons to act as the probe of magnetism. They were then able to follow the evolution of the magnetism into the metallic state.

“To our surprise, we found that the magnetism survives and is in some ways strengthened,” co-author Dr. Siddharth Saxena, group leader at the Cavendish Laboratory. “This is unexpected, as the newly-freely-roaming electrons in a newly conducting material can no longer be locked to their parent iron atoms, generating magnetic moments there — unless the conduction is coming from an unexpected source.”

In their previous paper, the researchers showed these electrons were ‘frozen’ in a sense. But when they made them flow or move, they started interacting more and more. The magnetism survives, but gets modified into new forms, giving rise to new quantum properties in a new type of magnetic metal.

How a material behaves, whether conductor or insulator, is mostly based on how the electrons, or charge, move around. However, the ‘spin’ of the electrons has been shown to be the source of magnetism. Spin makes electrons behave a bit like tiny bar magnets and point a certain way. Magnetism from the arrangement of electron spins is used in most memory devices: harnessing and controlling it is important for developing new technologies such as spintronics, which could transform the way in which computers process information.

“The combination of the two, the charge and the spin, is key to how this material behaves,” said co-author Dr David Jarvis from the Institut Laue-Langevin, France, who carried out this work as the basis of his PhD studies at the Cavendish Laboratory. “Finding this sort of quantum multi-functionality is another leap forward in the study of these materials.”

“We don’t know exactly what’s happening at the quantum level, but at the same time, we can manipulate it,” said Saxena. “It’s like those famous ‘unknown unknowns’: we’ve opened up a new door to properties of quantum information, but we don’t yet know what those properties might be.”

There are more potential chemical compounds to synthesize than could ever be fully explored and characterized. But by carefully selecting and tuning materials with special properties, it is possible to show the way towards the creation of compounds and systems, but without having to apply huge amounts of pressure.

Additionally, gaining fundamental understanding of phenomena such as low-dimensional magnetism and superconductivity allows researchers to make the next leaps in materials science and engineering, with particular potential in energy efficiency, generation and storage.

As for the case of magnetic graphene, the researchers next plan to continue the search for superconductivity within this unique material. “Now that we have some idea what happens to this material at high pressure, we can make some predictions about what might happen if we try to tune its properties through adding free electrons by compressing it further,” said Coak.

“The thing we’re chasing is superconductivity,” said Saxena. “If we can find a type of superconductivity that’s related to magnetism in a two-dimensional material, it could give us a shot at solving a problem that’s gone back decades.”

Reference: “Emergent Magnetic Phases in Pressure-Tuned van der Waals Antiferromagnet FePS3” by Matthew J. Coak, David M. Jarvis, Hayrullo Hamidov, Andrew R. Wildes, Joseph A. M. Paddison, Cheng Liu, Charles R. S. Haines, Ngoc T. Dang, Sergey E. Kichanov, Boris N. Savenko, Sungmin Lee, Marie Kratochvílová, Stefan Klotz, Thomas C. Hansen, Denis P. Kozlenko, Je-Geun Park and Siddharth S. Saxena, 5 February 2021, Physical Review X.
DOI: 10.1103/PhysRevX.11.011024

2 Comments on "A New Kind of Magnetism Formed by “Magnetic Graphene” – Could Reveal Secrets of Superconductivity"

  1. “how’d you measure the magnetism?-

    “Oh yeah, we had to invent our own probes for that..”

    “Yeeaaahhh… I’m gonna need to see some more uh… Testing..”

  2. Magnetism is the flow of dark-energy-radiation that takes place because the structure of a majority of the atoms (electrons) in a material, are aligned in one direction. This creates a north pole and an opposite end south pole. In two bar magnets, like poles (north to north, or south to south) strongly repel each other. Opposing poles, (north to south, or south to north) strongly attract each other. Normally dark-energy-radiation that surrounds atoms energizes them randomly. But because of the structured alignment of electrons (spin-structure) in magnetized material, dark-energy-radiation is more strongly vector-directed to energize the atoms by traveling in only one direction. So opposing magnetic force; is the force of focused dark-energy-radiation, engaging an opposing flow of focused dark-energy-radiation; the attracted magnetic force, is the directed flow of focused dark-energy through one magnet into the like-structure-aligned spinning-atoms (directed flow) of the second magnet. This naturally continually energizes the atoms, but also creates the magnetic force; (which is focused/directed dark-energy-radiation; gravity). So when we try to press two bar magnets together, N pole to N pole (or S pole to S pole), we can feel the flow and force of the energizing, radiating dark-energy-radiation, (which we call magnetism). Magnetic lines-of-flux appear, because the flow of DER is most-predominately through the N and S poles of the magnetic material, and DER surrounding this fast-flowing stream of dark-energy-radiation is being somewhat obstructed, thus creating magnetic lines-of-flux, surrounding any magnetic-structure.
    ———-
    Dark-energy radiation comprises ninety-five percent of our universe, visible mass only five percent. Our universe was created when “pure-energy” (existing in a closed, vacuum envionment), and possessing an ultra-weak positive-charge, suddenly combined with the surrounding “dark-matter-sea”, which possessed an ultra-weak negative-charge. The electrical explosive-reaction created a plasma of two substances; quarks/protons (which had a positive charge), and electrons (which have a negative charge). As the plasma cooled, together they created hydrogen atoms, the only original mass in our universe.
    Since the original “dark-matter-sea” exists in an absolute-zero temperature environment, our expanding-universe was shaped out of the surrounding sea of “dark-matter”, by the heat and energy present in the creation of mass; when the explosive-reaction of ultra-weak positive-charge “pure-energy”, was combined with the ultra-weak negative-charge “dark-matter-sea”. The present-limits of our expanding-universe are determined by the heat difference between the surrounding, absolute-zero temperature of the “dark-matter-sea” our sphere-shaped universe exists in; and the heat-and-energy temperature of our physical/visible universe. The heat and energy from our universe creates the release of dark-energy-radiation, from the absolute-zero-temperature “dark-matter-sea” that surrounds our universe. This dark-energy-radiation, charges, energizes/vibrates atoms; and this also accounts for our ever expanding-universe. “Space” does not exist. What we’ve known as “space”, is diffuse “dark-energy-radiation, radiating from the “dark-matter-sea” surrounding our sphere shaped universe; much like a gas-bubble existing in a loaf of bread. Uniform dark-energy-radiation explains why all massive objects in the universe are spherical shaped; and galaxies are spirals or spheres.
    “Time” is the energizing (charging) of atoms by Dark Energy Radiation; this is how atoms have been able to exist for 13.7 billion years.
    Light photons, or any electromagnetic wave, have no inherit means of propulsion; they are all identical, and vary only in length and frequency. They travel across the universe riding on dark-energy-radiation as a diffused-wave, and travel at 186,000 miles-per-second (“the speed of light”). Light photons are massless and have an ultra-weak positive charge. They are carried along by dark-energy-radiation until they encounter an electron of an atom-mass. A moving photon is diffuse, and is “spread-out” along the entire length of the discrete dark-energy-radiation wave. The photon becomes particle-like only upon encountering mass; striking an atom’s electron. There photons are deposited on the negative charge of an electron. In the two-slit experiment, a diffused-wave (spread-out) photon enters both slits, and then each of the two parts of the discrete-wave becomes a point-particle upon contacting any surface; an atom’s electron.

    Magnetism is the flow of dark-energy-radiation that takes place because the structure of a majority of the atoms (electrons) in a material, are aligned in one direction. This creates a north pole and an opposite end south pole. In two bar magnets, like poles (north to north, or south to south) strongly repel each other. Opposing poles, (north to south, or south to north) strongly attract each other. Normally dark-energy-radiation that surrounds atoms energizes them randomly. But because of the structured alignment of electrons (spin-structure) in magnetized material, dark-energy-radiation is more strongly vector-directed to energize the atoms by traveling in only one direction. So opposing magnetic force; is the force of focused dark-energy-radiation, engaging an opposing flow of focused dark-energy-radiation; the attracted magnetic force, is the directed flow of focused dark-energy through one magnet into the like-structure-aligned spinning-atoms (directed flow) of the second magnet. This naturally continually energizes the atoms, but also creates the magnetic force; (which is focused/directed dark-energy-radiation; gravity). So when we try to press two bar magnets together, N pole to N pole (or S pole to S pole), we can feel the flow and force of the energizing, radiating dark-energy-radiation, (which we call magnetism). Magnetic lines-of-flux appear, because the flow of DER is most-predominately through the N and S poles of the magnetic material, and DER surrounding this fast-flowing stream of dark-energy-radiation is being somewhat obstructed, thus creating magnetic lines-of-flux, surrounding any magnetic-structure.

    Time, is the charging and recharging of atoms throughout the Universe by the flow of dark-energy-radiation, as atoms are constantly being charged and recharged/renewed by the flow of dark-energy-radiation. Any previous state of atom-vibrations constitute the past, present atom-vibrations create the present, and future atom-vibrations will produce a future; so of course the atoms of your body can never go back into the past, to a past-vibrational-state. Matter, consisting of atoms, can exist for billions of years, only because of the continual charging and recharging of atoms in any massive body.

    Gravity, being just one of the four known forces powered by dark-energy-radiation; gives us the numeric-value of negative charge for dark-energy-radiation.
    —————————————————————————————————-
    In SI units, the 2006 CODATA recommended value of the gravitational constant is:
    G=(6.67428) x 10^-11 m^3 kg^-1 s^-2

    So, considering the force of dark-energy-radiation as Gravity; the force acting on one-kg of mass on the earth, for one-second-sq would be:
    6.67428 x 10^-11 / 1 this equals: 6.67428 x 10^-11

    and because of the inherit character (nature/action) of dark-energy-radiation, this needs to be divided by c-square: 300,000,000 mps^2 (which equals) (9 x 10^16)
    This gives: 6.67428 x 10^-11 / 9 x 10^16 (which equals) = 7.415866667 x 10^-28

    So, 7.415866667 x 10^-28 is the ultra-weak, negative-electrical charge of dark-energy-radiation energizing/vibrating (creating a charge) for one-kg of atoms on the earth, for 1-second.

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