Berkelium

Berkelium (Bk) — 10-Year Trends

As of 2026-09-25 · the last 10 years

Berkelium’s research intensity sits at about 9% of its own all-time peak, a level that has held steady since the window began, even though the element’s historical peak occurred in 1959.

Research intensity ran from about 9% of the element's own all-time peak in 2016 to about 9% in 2026 — essentially flat across the window, and the all-time peak (1959) lies before this window. Over the same span its share of research attention across all elements held steady. Among the 118 elements, berkelium has one of the smaller research literatures of any element.

The number of papers involving the element rose from about 23 in 2016 to about 39 in 2025 (1.7x). That is slower than the literature as a whole grew over the same years, so the element lost ground in the wider body of research even as its own count rose.

The bulk of berkelium’s recent work belongs to a subcommunity focused on Berkelium Carbon Bonding in Actinide Chemistry. These papers investigate the formation of carbon-berkelium bonds and the structural properties of berkelium(III) species, with distinctive attention to berkelium-carbon interactions and comparisons with californium. In this context, berkelium is a minor presence in a much larger community, with under 1% of its papers involving berkelium. This area accounts for about 48% of the element's recent research, a share that has declined from about 58% in the previous period. A key recent contribution is the 2025 Science paper "Berkelium–carbon bonding in a tetravalent berkelocene," cited about 18 times, which explores these bonding properties.

The second major area is Superheavy Nuclei, Heavy-Ion Collisions, and Nuclear Structure. This community deals with the synthesis of elements and the dynamics of superheavy nuclei, often involving sequential fission and synthesis reactions. Here too, berkelium is a minor presence in a much larger community, with under 1% of its papers involving berkelium. However, this is where the element’s literature is consolidating: its share of berkelium research has risen significantly, from about 24% to about 39% over the window. A notable paper in this space is the 2023 Nature Communications article "Colliding heavy nuclei take multiple identities on the path to fusion," cited about 25 times.

A smaller, steady portion of the work falls under Uranium Extraction, Separation, and Nuclear Fuel Cycle Chemistry. Berkelium remains a minor presence in this community as well, with under 1% of its papers involving the element. This area holds about 4% of the element's recent research, a share that has remained steady. The 2019 Annals of the ICRP publication "ICRP Publication 141: Occupational Intakes of Radionuclides: Part 4," cited about 98 times, is a significant reference in this field.

Overall, the composition of berkelium research has shifted: the share of work in carbon bonding has declined, while the share in superheavy nuclei and nuclear structure has risen. The remaining research, comprising about 9% of the element's work, is spread across other communities. For a deeper look at the current state of berkelium research, see the element’s Last 12 Months report.