Liquid Carbon

Liquid Carbon Latest News

Scientists have for the first time observed the atomic structure of liquid carbon using the high-power DIPOLE 100-X laser and ultrashort X-ray pulses from the European XFEL (X-ray Free Electron Laser) in Germany.

About Liquid Carbon

• Liquid carbon refers to carbon in a liquid state, which is not naturally stable under normal temperature and pressure conditions.
• Carbon typically exists in solid forms like graphite, diamond, or as gas (CO₂) when oxidised.
• Liquid carbon is a transient phase, and its study is important for understanding:
  • Planetary core compositions (e.g., carbon-rich exoplanets),
  • High-energy astrophysical processes,
  • And high-temperature material behaviour in laser-material interactions and nuclear science.

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Why Liquid Carbon Is Hard to Study

• Carbon does not melt under normal pressure; it transitions directly from solid to gas (sublimation), making lab-based liquid-phase studies almost impossible.
• Liquid carbon only forms under extreme conditions:
  • Temperatures ~4500°C,
  • Very high pressures,
  • Conditions that no conventional container can withstand.
• Thus, laser-driven compression was employed to briefly liquefy solid carbon for nanoseconds, enabling real-time measurement.

Experimental Technique and Innovation

• The DIPOLE 100-X laser was used to generate compression waves through the carbon sample, converting it to the liquid state for a billionth of a second.
• During this fleeting moment, the European XFEL’s ultrashort X-ray pulse was used to irradiate the sample, causing the X-ray light to diffract off atoms.
• The resulting diffraction pattern revealed the atomic arrangement of liquid carbon.
• Multiple iterations of the experiment with varying delays and conditions were used to create a step-by-step “movie” of the solid-to-liquid transition.

Major Findings of the Study

• Liquid carbon has a water-like structure, with four nearest atomic neighbours, resembling the structure of solid diamond.
• The experiment confirmed earlier theoretical simulations and helped to precisely determine the melting point of carbon under high pressure.
• These insights are important for:
  • Planetary science, as liquid carbon exists in the interiors of planets.
  • Nuclear fusion technology, where carbon-based materials are often involved under extreme conditions.

Liquid Carbon FAQs

Q1: What is Liquid Carbon?
Ans: Liquid Carbon refers to carbon in a liquid state, which is not naturally stable under normal temperature and pressure.

Q2: Why is Liquid Carbon rare?

Ans: It typically forms only under extreme conditions like temperatures above 4500°C and very high pressure, making it transient and difficult to study in laboratory settings.

Source: PHY