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<p>High-entropy carbides (HECs) are a new class of compositionally complex ceramics with exceptional stability under high temperatures, corrosion, and intense irradiation. Their multi-principal metal sublattice with C anions produces a complex energy landscape distinct from medium/high-entropy alloys (M/HEAs), where bonding is primarily metallic. Although chemical short-range order (CSRO) in HEAs suppresses defect mobility and enhances defect recovery, its role in HECs remains unclear. Here, we discover that, in contrast to M/HEAs, CSRO in HECs can accelerate defect diffusion and that diffusion is dominated by a single metal species. This accelerated mobility drives radiation-induced segregation (RIS). Predictions of defect kinetics were made using molecular dynamics based on machine learning potentials in (NbTiVZr)C and (NbTiVMo)C, and the presence of RIS was confirmed experimentally in (NbTiVMo)C. Our results reveal that the interplay between CSRO and chemical composition controls defect kinetics and GB compositional evolution, providing a mechanistic foundation for designing HECs with tailored radiation resistance for extreme environment applications.</p>

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Chemical short-range order accelerates defect diffusion in high-entropy carbides

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2026年7月19日

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  • Muhammad Waqas Qureshi,
  • Shuguang Wei,
  • Ajay Annamareddy,
  • Jiaxing Chen,
  • Jiangjiang Mao,
  • Hongliang Zhang,
  • Izabela Szlufarska

摘要

High-entropy carbides (HECs) are a new class of compositionally complex ceramics with exceptional stability under high temperatures, corrosion, and intense irradiation. Their multi-principal metal sublattice with C anions produces a complex energy landscape distinct from medium/high-entropy alloys (M/HEAs), where bonding is primarily metallic. Although chemical short-range order (CSRO) in HEAs suppresses defect mobility and enhances defect recovery, its role in HECs remains unclear. Here, we discover that, in contrast to M/HEAs, CSRO in HECs can accelerate defect diffusion and that diffusion is dominated by a single metal species. This accelerated mobility drives radiation-induced segregation (RIS). Predictions of defect kinetics were made using molecular dynamics based on machine learning potentials in (NbTiVZr)C and (NbTiVMo)C, and the presence of RIS was confirmed experimentally in (NbTiVMo)C. Our results reveal that the interplay between CSRO and chemical composition controls defect kinetics and GB compositional evolution, providing a mechanistic foundation for designing HECs with tailored radiation resistance for extreme environment applications.