JNCASR Study Shows Spin‑Phonon Coupling Raises Heat Conductivity in Magnetic Semiconductor CrN Scientists from the JNCASR , in collaboration with IISER Thiruvananthapuram and international partners, have experimentally identified why certain magnetic semiconductors exhibit an increase in thermal conductivity above their magnetic transition temperature. The work, published in Science Advances , provides the first direct evidence linking spin‑phonon coupling to anomalous heat transport. Key Developments Using temperature‑dependent inelastic X‑ray scattering , the team measured phonon lifetimes in high‑quality epitaxial CrN thin films across the magnetic phase transition. Acoustic phonons, the primary heat carriers, showed strong damping near the Néel temperature due to intense interaction with magnetic spin fluctuations. Above this temperature, as long‑range magnetic order weakens, phonon lifetimes increase, leading to an unexpected rise in thermal conductivity. Optical phonons followed conventional temperature behaviour, confirming that the anomaly is specific to acoustic phonons and spin fluctuations. Atomistic spin‑dynamics simulations and first‑principles calculations corroborated the experimental observations, establishing a microscopic mechanism. Important Facts Material studied: Chromium Nitride ( CrN ), a magnetic semiconductor used in coatings and electronic components. Temperature range: Measurements performed from below to well above the Néel temperature (~300 K to 373 K). Technique: High‑resolution inelastic X‑ray scattering at synchrotrons SPring‑8 (Japan) and DESY (Germany). Collaborators: JNCASR, IISER Thiruvananthapuram, Linköping University (Sweden), and international synchrotron facilities. Publication: Science Advances , DOI: 10.1126/sciadv.adw7332. Relevance for UPSC The study touches upon several GS‑3 (Science & Technology) themes: material science, thermal management in electronics, and emerging technologies such as spintronics and quantum devices. Understanding heat transport mechanisms is vital for designing reliable high‑performance devices, a topic frequently asked in questions on technology and industry. From a policy perspective, the research showcases India's capability in high‑end materials research, aligning with the government's push for self‑reliance in advanced technology (Make in India, Atmanirbhar Bharat). It also underscores the role of autonomous research institutions under the DST in driving frontier science. Way Forward Explore tunable spin‑phonon interactions in other magnetic semiconductors to develop materials with controllable thermal conductivity. Integrate such materials into spintronic and quantum device architectures to mitigate heat‑related reliability issues. Strengthen collaborative research infrastructure, including access to international synchrotron facilities, to accelerate discovery. Formulate guidelines for thermal management in emerging high‑power magnetic devices, informing industry standards and government R&D policies. By linking magnetic fluctuations to heat flow, the study not only resolves a decade‑old scientific puzzle but also provides a strategic pathway for India to lead in next‑generation electronic and quantum technologies.