Controlling clouds-to-scars dislocations' transitions on spherical crystal shells

The closed topology of spherical crystals renders the presence of topological defects inevitable. These defects can organize in a plethora of different structures, such as "clouds"or grain boundary "scars", challenging for theoretical modeling and experimental visualization. Visualizing the defects by fluorescent dye adsorption, we reveal ion concentration control of a clouds-to-scars transition, which we attribute to commonly neglected defects' core energy. The consequent line tension energy probes the defects' molecular scale energetics, enabling pattern tuning for future applications.