Superionic materials are a class of materials that simultaneously present properties that are characteristic of solids and liquids. Essentially, a set of ions in these materials exhibits liquid-like mobility, even if the materials’ underlying atomic structure maintains a solid-like order.

Due to their unique ionic conductivity patterns, superionic materials could be promising for developing solid-state batteries. These are batteries that contain electrolytes based on solid materials instead of liquid electrolytes.

While various past studies have explored the potential of superionic materials as solid-state electrolytes, the physics underpinning their rapid ionic diffusion is not yet fully understood. Specifically, it is unclear whether this property results from liquid-like motion in the material or from the conventional lattice phonons (i.e., atom vibrations) in the material.

A research team has discovered that by using a new method of “atomic spray painting,” they can tweak the atomic structure of lead-free potassium niobate in order to enhance its ferroelectric properties.

The study, created by a team led by Penn State researchers, explains how molecular beam epitaxy can be employed to deposit atomic layers onto a substrate to create thin films, as a report by SciTechDaily explained.

Using a technique called strain tuning, the researchers adjusted how successive layers are aligned to modify a material’s properties by stretching or compressing the atoms that make up its crystal structure.

Chirality refers to objects that cannot be superimposed onto their mirror images through any combination of rotations or translations, much like the distinct left and right hands of a human. In chiral crystals, the spatial arrangement of atoms confers a specific “handedness,” which—for example—influences their optical and electrical properties.

A Hamburg-Oxford team has focused on so-called antiferro-chirals, a type of non-chiral crystal reminiscent of antiferro-magnetic materials, in which magnetic moments anti-align in a staggered pattern leading to a vanishing net magnetization. An antiferro-chiral crystal is composed of equivalent amounts of left-and right-handed substructures in a unit cell, rendering it overall non-chiral.

The research team, led by Andrea Cavalleri of the Max-Planck-Institut for the Structure and Dynamics of Matter, used terahertz light to lift this balance in the non-chiral material boron phosphate (BPO₄), in this way inducing finite chirality on an ultrafast time scale.