Dual phase patterning during a congruent grain boundary phase transition in elemental copper

• Published in: Nature communications Vol. 13; no. 1; pp. 3331 - 11
• Main Authors: Langenohl, Lena, Brink, Tobias, Freitas, Rodrigo, Frolov, Timofey, Dehm, Gerhard, Liebscher, Christian H.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09.06.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 147/143; 639/301/119/2795; 639/301/119/544; Boundaries; Computer applications; Copper; Elastic limit; Grain boundaries; Humanities and Social Sciences; Interfacial properties; Low temperature; MATERIALS SCIENCE; multidisciplinary; Pattern formation; Patterning; Phase transitions; phase transitions and critical phenomena; Phases; Pressure; Room temperature; Science; Science (multidisciplinary); surfaces, interfaces and thin films
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-30922-3

The phase behavior of grain boundaries can have a strong influence on interfacial properties. Little is known about the emergence of grain boundary phases in elemental metal systems and how they transform. Here, we observe the nanoscale patterning of a grain boundary by two alternating grain boundary phases with distinct atomic structures in elemental copper by atomic resolution imaging. The same grain boundary phases are found by computational grain boundary structure search indicating a first-order transformation. Finite temperature atomistic simulations reveal a congruent, diffusionless transition between these phases under ambient pressure. The patterning of the grain boundary at room temperature is dominated by the grain boundary phase junctions separating the phase segments. Our analysis suggests that the reduced mobility of the phase junctions at low temperatures kinetically limits the transformation, but repulsive elastic interactions between them and disconnections could additionally stabilize the pattern formation. The phase behavior of grain boundaries can influence the interfacial properties. Here the authors demonstrate nanoscale patterning of a grain boundary by two alternating phases in Cu that exhibit a congruent, diffusionless transition between the two phases.