5 ms·

‘Magnetic graphene’ switches between insulator and conductor

52 points by mangoleaf 8y ago

slyrus 8y ago
Is 10 gPa (is that the right capitalization for gigaPascal? Gigapascal? GigaPascal?) anyway? Is that something routinely used in the lab or in production of commercial materials like chips or other electronic equipment?
- msandford 8y ago
  10GPa is about 100k atmosphere or 1500ksi or 1.5 million psi. The best steels in the world are what are called maraging steel and they're 500ksi. Normal mild steel might only be 30ksi. So it's going to be tough to recreate this outside the lab I suspect.
- jonsen 8y ago
  Prefix name: giga Prefix symbol: G Unit name: pascal Unit symbol: Pa https://en.m.wikipedia.org/wiki/International_System_of_Units#Units_and_prefixes https://en.m.wikipedia.org/wiki/International_System_of_Unit...
apo 8y ago
Although the term "magnetic graphene" is sometimes used to refer to FePS3, this compound isn't graphene - it's devoid of carbons. Rather, FePS3, like graphene, has a tendency to form thin sheets. But that's where the similarities end. The original paper's abstract is more helpful than the article: Two-dimensional materials have proven to be a prolific breeding ground of new and unstudied forms of magnetism and unusual metallic states, particularly when tuned between their insulating and metallic phases. Here we present work on a new metal-to-insulator transition system FePS3. This compound is a two-dimensional van der Waals antiferromagnetic Mott insulator. We report the discovery of an insulator-metal transition in FePS3, as evidenced by x-ray diffraction and electrical transport measurements, using high pressure as a tuning parameter. Two structural phase transitions are observed in the x-ray diffraction data as a function of pressure, and resistivity measurements show evidence of the onset of a metallic state at high pressures. We propose models for the two new structures that can successfully explain the x-ray diffraction patterns. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.266801 https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.12... And this general-audience article is IMO better than the one linked: "The discovery of graphene led me to wonder if I could introduce magnetism to 2-D materials similar to graphene," explains Park. "Physicists have inherited the challenge of studying and explaining the physical properties of the two-dimensional world. In spite of its academic importance and applicability, this field is very much under-explored," he adds. https://phys.org/news/2018-10-flexy-flat-functional-magnets.html https://phys.org/news/2018-10-flexy-flat-functional-magnets....
julienfr112 8y ago
Graphene can do anything, but leave the lab.
- setquk 8y ago
  Yes. It can simultaneously cause and cure cancer too!

52 points by mangoleaf 8y ago

Is 10 gPa (is that the right capitalization for gigaPascal? Gigapascal? GigaPascal?) anyway? Is that something routinely used in the lab or in production of commercial materials like chips or other electronic equipment?

msandford 8y ago
10GPa is about 100k atmosphere or 1500ksi or 1.5 million psi. The best steels in the world are what are called maraging steel and they're 500ksi. Normal mild steel might only be 30ksi. So it's going to be tough to recreate this outside the lab I suspect.
jonsen 8y ago
Prefix name: giga Prefix symbol: G Unit name: pascal Unit symbol: Pa https://en.m.wikipedia.org/wiki/International_System_of_Units#Units_and_prefixes https://en.m.wikipedia.org/wiki/International_System_of_Unit...

apo 8y ago

Although the term "magnetic graphene" is sometimes used to refer to FePS3, this compound isn't graphene - it's devoid of carbons. Rather, FePS3, like graphene, has a tendency to form thin sheets. But that's where the similarities end. The original paper's abstract is more helpful than the article: Two-dimensional materials have proven to be a prolific breeding ground of new and unstudied forms of magnetism and unusual metallic states, particularly when tuned between their insulating and metallic phases. Here we present work on a new metal-to-insulator transition system FePS3. This compound is a two-dimensional van der Waals antiferromagnetic Mott insulator. We report the discovery of an insulator-metal transition in FePS3, as evidenced by x-ray diffraction and electrical transport measurements, using high pressure as a tuning parameter. Two structural phase transitions are observed in the x-ray diffraction data as a function of pressure, and resistivity measurements show evidence of the onset of a metallic state at high pressures. We propose models for the two new structures that can successfully explain the x-ray diffraction patterns. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.266801 https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.12... And this general-audience article is IMO better than the one linked: "The discovery of graphene led me to wonder if I could introduce magnetism to 2-D materials similar to graphene," explains Park. "Physicists have inherited the challenge of studying and explaining the physical properties of the two-dimensional world. In spite of its academic importance and applicability, this field is very much under-explored," he adds. https://phys.org/news/2018-10-flexy-flat-functional-magnets.html https://phys.org/news/2018-10-flexy-flat-functional-magnets....

julienfr112 8y ago

Graphene can do anything, but leave the lab.

setquk 8y ago
Yes. It can simultaneously cause and cure cancer too!