A research team has discovered how to make a promising energy-harvesting material much more efficient—without relying on rare or expensive elements. The material, called β-Zn₄Sb₃, is a tellurium-free thermoelectric compound that can convert waste heat into electricity.

In their study published in Advanced Science, scientists used advanced neutron scattering techniques to peek inside the crystal and found something surprising: tiny heat vibrations (called phonons) were being disrupted by “rattling” atoms inside the structure. This phenomenon, known as phonon avoided crossing, dramatically slowed down how heat travels through the material.

Thanks to this effect, the material’s thermal conductivity dropped to extremely low levels—great news for thermoelectric performance. Even better, the researchers found that the single-crystal version of this material also conducts electricity better than its polycrystalline counterpart, reaching a high power conversion efficiency of 1.4%.

Magnets and superconductors go together like oil and water—or so scientists have thought. But a new finding by MIT physicists is challenging this century-old assumption.

In a paper appearing in the journal Nature, the physicists report that they have discovered a “chiral superconductor”—a material that conducts electricity without resistance, and also, paradoxically, is intrinsically magnetic. What’s more, they observed this exotic superconductivity in a surprisingly ordinary material: graphite, the primary material in pencil lead.

Graphite is made from many layers of graphene—atomically thin, lattice-like sheets of carbon atoms—that are stacked together and can easily flake off when pressure is applied, as when pressing down to write on a piece of paper. A single flake of graphite can contain several million sheets of graphene, which are normally stacked such that every other layer aligns. But every so often, graphite contains tiny pockets where graphene is stacked in a different pattern, resembling a staircase of offset layers.