Coherent and Semi-coherent Interfaces

This lecture covers the concepts of coincidence lattice, homophase interfaces, key topics in the previous class, defects at coherent homophase interfaces, ledges and grain boundaries, twin boundaries, stacking faults, and segregation at domain boundaries. The instructor discusses the relationship between twins and stacking faults, the reversible roughening-faceting transformation, and the segregation of impurities at grain boundaries. The lecture concludes with insights on tuning the stability and mechanical properties of grain boundaries by impurities. Various analytical techniques and theoretical models are presented to understand the behavior of interfaces.