Interface by definition is two-dimensional (2-D) as it separates 2 phases with an abrupt change in structure and chemistry across the interface. The interface between a metal and its nitride is expected to be atomically sharp, as chemical gradation would require the creation of N vacancies in nitrides and N interstitials in metal. Contrary to this belief, using first-principles density functional theory (DFT), we establish that the chemically graded Ti/TiN interface is thermodynamically preferred over the sharp interface. DFT calculated N vacancy formation energy in TiN is 2.4 eV, and N interstitial in Ti is -3.8 eV. Thus, diffusion of N from TiN to Ti by the formation of N vacancy in TiN and N interstitial in Ti would reduce the internal energy of the Ti-TiN heterostructure. We show that diffusion of N is thermodynamically favorable till ~23% of N has diffused from TiN to Ti, resulting in an atomically chemically graded interface, which we refer to as a 3-D interface. Experiments' inability to identify a 3-D interface in Ti/TiN could be attributed to limitations in identifying chemical composition and structure with atomic-level resolution at interfaces. We define the sum of N vacancy formation energy and N interstitial formation energy as driving-force, which could be used as a convenient way to assess the possibility of forming a 3-D interface in metal/ceramic heterostructures. We also show gradual variation in lattice parameters and mechanical properties (like bulk modulus, shear modulus, Young's modulus, and hardness) across the Ti/TiN interface. 3-D interfaces open a new way to control properties of metal/ceramic heterostructures, in line with the already established advantage of gradation at interfaces in micrometer length scale. For widely explored Ti/TiN multilayer nano-heterostructures, the possibility of forming 3-D interface could lead to enhanced wear and erosion resistance.
Rate Equation for the Transfer of Interstitials across Interfaces between Equilibrated Crystals
Hamburg University of Technology（汉堡工业大学）；Institute of Materials Physics and Technology, Hamburg University of Technology（汉堡工业大学材料物理与技术研究所）；Helmholtz-Zentrum Hereon（亥姆霍兹海雷恩中心）；Institute of Hydrogen Technology, Helmholtz-Zentrum Hereon（亥姆霍兹海雷恩中心氢能技术研究所）
Suppression of material transfer at contacting surfaces: The effect of adsorbates on Al/TiN and Cu/diamond interfaces from first-principles calculations
Mechanism for Radiation Damage Resistance in Yttrium Oxide Dispersion Strengthened Steels
基于氧化钇的ODS钢由于其观察到的抗辐射性能而被建议作为潜在的聚变反应堆壁材料。据推测，这种耐辐射性可能与粒子与空位、自填隙原子（SIAs）和其他辐射损伤碎片的相互作用有关。密度泛函理论已被用于在原子尺度上研究这一点。四个不同的界面，一些基于HRTEM观察，铁和氧化钇之间进行了研究。结果表明，Y $_2$ O $_3$ -Fe界面作为一个强大的陷阱与长程吸引的间隙和空位缺陷，允许重组而不改变界面结构。在不改变微观结构的情况下催化消除缺陷解释了ODS钢在辐射蠕变和溶胀方面的改进行为。
Interface-Enhanced Superconductivity in Ultrathin TiN Proximitized by Topological Insulators
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences（中国科学院宁波材料技术与工程研究所）；Eastern Institute for Advanced Study, Eastern Institute of Technology（宁波东方理工大学（暂名）先进研究院）；The Instruments Center for Physical Science, University of Science and Technology of China（中国科学技术大学物理科学仪器中心）；Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences（中国科学院理化技术研究所功能晶体与激光技术重点实验室）；Yongjiang Laboratory（甬江实验室）；Department of Physics & Astronomy, Rutgers, The State University of New Jersey（新泽西州立罗格斯大学物理与天文系）
Interface-Controlled Defect Engineering in TiN/TaN Superlattices for Enhanced Hardness and Fracture Toughness
Technische Universität Wien（维也纳工业大学）；Plansee (Shanghai) High Performance Material Ltd.（普莱思（上海）高性能材料有限公司）；Guangdong University of Technology（广东工业大学）；RWTH Aachen University（亚琛工业大学）；Austrian Academy of Sciences（奥地利科学院）；Uppsala University（乌普萨拉大学）
Phenothiazine-Based Self-Assembled Monolayer with Thiophene Head Groups Minimizes Buried Interface Losses in Tin Perovskite Solar Cells
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH（柏林赫尔姆霍兹材料能源中心）；University of Naples Federico II（那不勒斯费德里科二世大学）；University of Bielefeld（比勒费尔德大学）；Humboldt-Universität zu Berlin（柏林洪堡大学）；Kaunas University of Technology（考纳斯理工大学）；Istituto Italiano di Tecnologia (IIT)（意大利理工学院）
Developing Potential Energy Surfaces for Graphene-based 2D-3D Interfaces from Modified High Dimensional Neural Networks for Applications in Energy Storage
