Frank–Read source

In materials science, a Frank–Read source is a mechanism explaining the generation of multiple dislocations in specific well-spaced slip planes in crystals when they are deformed.

The mechanism of dislocation generation was proposed by and named after British physicist Charles Frank and Thornton Read.

In 2024, Cheng Long and coworkers demonstrated that the Frank-Read mechanism can generate disclination loops in nematic liquid crystals.

[1] This finding suggests that the Frank-Read mechanism may arise in a broader class of materials containing topological defect lines.

[2] In 1950 Charles Frank, who was then a research fellow in the physics department at the University of Bristol, visited the United States to participate in a conference on crystal plasticity in Pittsburgh.

Frank arrived in the United States well in advance of the conference to spend time at a naval laboratory and to give a lecture at Cornell University.

When, during his travels in Pennsylvania, Frank visited Pittsburgh, he received a letter from fellow scientist Jock Eshelby suggesting that he read a recent paper by Gunther Leibfried.

A couple of days later, he traveled to the conference on crystal plasticity in Pittsburgh where he ran into Thornton Read in the hotel lobby.

Upon encountering each other, the two scientists immediately discovered that they had come up with the same idea for dislocation generation almost simultaneously (Frank during his walk at Cornell, and Thornton Read during tea the previous Wednesday) and decided to write a joint paper on the topic.