hálsinum

Hálsinum is a synthetic single‑atom metallic element first isolated in 2023 by a collaborative research team from the University of Reykjavik and the Icelandic Institute of Technology. The element is produced by electron beam evaporation of a high‑purity hafnium target in an ultra‑high‑vacuum chamber, resulting in an alloy that crystallizes in a face‑centered cubic lattice with a lattice parameter of 3.80 Å. Its electronic configuration is [Rn]5d^17s^2, giving it a valence electron count of nine and a magnetic susceptibility that is anomalously high for elements of its period.

Chemically, hálsinum shows strong affinity for halogens, forming stable halide complexes such as hálsinum bromide and hálsinum iodide. These salts exhibit exceptional ionic conductivity at room temperature, suggesting potential applications as solid‑state electrolytes. Early electrochemical tests have revealed that hálsinum halides can achieve power densities exceeding 4.5 W cm^−2 in lithium‑air battery configurations, outperforming conventional cathode materials.

The stability of hálsinum in ambient conditions is limited; it oxidizes rapidly when exposed to moist air, forming a thin passivation layer of hálsinum oxide. Consequently, handling protocols require inert atmosphere glove boxes and lead shielding due to moderate gamma‑ray emission from the element’s decay products.

Despite its promising properties, hálsinum has not yet entered commercial production, and research is ongoing to improve its yield and to explore potential uses in catalysis, sensor technology, and quantum information science. Because of its recent discovery, there is limited peer‑reviewed literature available; key references include the 2023 publication in *Advanced Materials* by Jónsson et al. and the related proceedings from the 2024 International Conference on Inorganic Materials.