(Auburn, AL) Imagine a cloud that shines like a neon sign, but instead of raindrops it contains countless microscopic dust grains floating in midair. This is a dusty plasma, a bizarre state of matter found both in deep space and in the laboratory.
In a new study, published this week in Physical Review E, Auburn University physicists report that even weak magnetic fields can reshape how these dusty plasmas behave—slowing down or speeding up the growth of nanoparticles suspended inside. Their experiments show that when a magnetic field nudges electrons into spiraling paths, the entire plasma reorganizes, changing how particles charge and grow.
"Dusty plasmas are like tiny particles in a vacuum box," said Bhavesh Ramkorun, lead author of the study. "We found that by introducing magnetic fields, we could make these particles grow faster or slower, and the dust particles ended up with very different sizes and lifetimes."
The researchers grew carbon nanoparticles by igniting a mix of argon and acetylene gas. Normally, particles grew steadily for about two minutes before drifting away. With magnetic fields, the cycle shortened dramatically—sometimes to under a minute—and the particles stayed smaller.
"It's remarkable how sensitive the system is," explained Saikat Thakur, co-author. "Electrons are the lightest players in the plasma, but when they become magnetized, they dictate the rules. That simple change can completely alter how nanomaterials form."
The results could help scientists design new plasma-based techniques for creating nanoparticles with tailored properties for electronics, coatings, and quantum devices. At the same time, they offer fresh insight into natural plasmas in space, from planetary rings to the solar atmosphere, where dust and magnetic fields are constantly interacting.
"Plasma makes up most of the visible universe, and dust is everywhere," added Ramkorun. "By studying how the smallest forces shape these systems, we're uncovering patterns that connect the lab to the cosmos."
About Auburn Physics:
The Department of Physics at Auburn University is home to pioneering research in plasma physics, where scientists combine cutting-edge experiments with advanced theory and simulation while training the next generation of physicists through hands-on research and discovery. Graduate admissions are now open for students eager to join Auburn's vibrant research community and contribute to advancing plasma, biophysics, and materials science.
