Scientists have revealed new details about a conductive form of nickel oxide that was previously identified and is believed to exist deep inside the Earth, according to the press service of the Russian Science Foundation. The discovery adds a crucial piece to the puzzle of how materials behave under extreme conditions and what that means for our understanding of planetary interiors.
Officials described the results as a significant step forward in grasping the basic properties of this unusual insulator when it is subjected to pressure far beyond ordinary environments. The researchers noted that such insights are particularly relevant to geophysics and the study of the Earth’s structure, including how materials may change phase under the intense forces found deep underground, which has implications for interpreting seismic data and the dynamics of planetary cores.
Under normal circumstances, nickel oxide acts as an insulator, resisting the flow of electric current. However, historical theoretical work by British physicist Neville Mott in the mid-20th century proposed that nickel oxide could undergo a transition to a metallic state when placed under sufficiently high pressure. This idea, once debated and difficult to test, has gradually moved closer to experimental confirmation through advances in high-pressure science.
Recent experiments by scientists at the Nuclear Research Institute of the Russian Academy of Sciences in Moscow have provided a clearer answer. By compressing nickel monoxide crystals to about 2.4 million atmospheres of pressure, the researchers observed a transition in which the material began to conduct electricity. The change indicates a shift in the electronic structure of the material, allowing charge carriers to move more freely and enabling metallic conduction. This phenomenon showcases how pressure can alter bonding and electron behavior in transition metal oxides, driving material properties into a new regime that was once only theoretical. These findings were communicated by the RSF press service as a part of ongoing efforts to map the behavior of minerals under extreme conditions and to inform models of how the Earth’s interior might respond to immense forces at great depths.
The broader context of the work highlights a long-standing curiosity about the state of matter under the kind of pressures believed to exist in the Earth’s inner regions. Researchers emphasize that understanding when and how materials like nickel oxide switch from insulators to conductors can shed light on geophysical processes, including heat transfer, electrical conductivity, and the possible distribution of elements within the core. The discovery aligns with a growing body of laboratory results that simulate the extreme environments of planetary interiors, contributing to more accurate interpretations of seismic signals and the overall dynamics shaping our planet. In addition to advancing basic science, these results may influence models of planetary formation and geophysical phenomena across the solar system, where similar materials could behave differently under varying pressure regimes and temperatures. The work underscores the value of high-pressure experimentation as a bridge between theoretical predictions and real-world observations, offering a tangible glimpse into how matter behaves when pushed to the limits.
In a related note, the size and characteristics of Earth’s inner core continue to be subjects of scientific inquiry. Geophysicists estimate that the central region of the core extends to about 650 kilometers in radius, though its exact properties remain a focus of ongoing research. The recent findings about nickel oxide contribute to a broader effort to infer the composition and behavior of core materials, helping scientists refine their models of how the Earth stores energy and conducts heat deep below the surface. While the experiments described were conducted in controlled laboratory settings, the implications reach far beyond the lab benches, potentially informing our understanding of planetary differentiation, magnetic field generation, and the deep-time evolution of Earth-like worlds. Attribution for these insights goes to the RSF press service, which notes the importance of continuing investigations into the behavior of transition metal oxides under extreme compression and their relevance to geoscience and planetary science.