Research led by Edward Thomas Jr., professor of physics at Auburn University, is shedding new light on how an unusual state of matter responds to magnetism that would normally be considered too weak to matter. The work focuses on dusty plasma, a form of plasma that contains solid nanoparticles suspended within an ionized gas, and shows that even modest magnetic fields can substantially alter how such systems evolve.
Ramkorun, B., Thakur, S. C., Comes, R. B., & Thomas, E. (2025). Electron magnetization effects on carbonaceous dusty nanoparticles grown in <math> <mrow> <mi>Ar</mi> <mtext>−</mtext> <msub> <mi mathvariant="normal">C</mi> <mn>2</mn> </msub> <msub> <mi mathvariant="normal">H</mi> <mn>2</mn> </msub> </mrow> </math> capacitively coupled nonthermal plasma. Physical Review E, 112(4), 045211. https://doi.org/10.1103/3d3h-rkmb
Dusty plasmas occur in both engineered and natural environments, from semiconductor processing chambers to planetary rings and interstellar clouds. While electric fields are known to dominate their behavior, the influence of weak magnetic fields has remained uncertain. Thomas and his colleagues demonstrate that magnetism can play a decisive role by acting on the lightest component of the plasma: electrons.
Edward Thomas Jr., professor of physics at Auburn University stated,
“Plasma makes up most of the visible universe, and dust is everywhere. By studying how the smallest forces shape these systems, we’re uncovering patterns that connect the lab to the cosmos.”
The experiments examined how carbon nanoparticles form inside a low-temperature, nonthermal plasma generated from a mixture of argon and acetylene gas. Under typical laboratory conditions without magnetic influence, nanoparticles grew steadily and remained suspended for roughly two minutes before leaving the plasma. When a magnetic field was introduced, that growth window shortened significantly, and the particles that formed were smaller and less persistent.
The key factor was electron magnetization. Because electrons are much lighter than ions or dust particles, they respond first to magnetic fields. Once magnetized, their motion becomes constrained into curved, spiral paths. This change affects how charge is distributed throughout the plasma and alters the way dust particles accumulate electrons, which directly influences their growth rate.
Graduate researcher Bhavesh Ramkorun, the study’s lead author, explains that the system is highly sensitive to these changes. Even when the magnetic field is too weak to noticeably affect heavier plasma components, the altered behavior of electrons is enough to reshape the entire environment. Co-author Saikat Thakur notes that this highlights the central role electrons play in determining plasma structure, despite representing only a small fraction of its mass.
The findings extend beyond the laboratory. Many space plasmas exist in weakly magnetized regions where electrons are influenced by magnetic fields while heavier particles are not. The results suggest that dust formation in these environments may depend more strongly on magnetic conditions than previously assumed, affecting models of planetary rings, cometary tails, and astrophysical dust clouds.
From an engineering standpoint, the study points to new approaches for controlling plasma-based nanoparticle synthesis. Rather than modifying gas composition or power input, engineers could potentially use magnetic fields to fine-tune particle size and lifetime. This level of control could be valuable in applications such as thin-film deposition, coatings, and electronic materials where nanoscale precision is essential.
Overall, the work emphasizes a recurring theme in plasma physics: small forces acting on the lightest particles can dictate the behavior of the entire system. By showing how weak magnetism reshapes dusty plasmas through electron dynamics, the study bridges practical plasma engineering with broader questions about how matter assembles throughout the universe.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
