Often the vortex pinning can be increased by making the individual crystallites (or grains) of the material smaller, thus increasing the surface area associated with grain boundaries, where vortices get pinned.
Often the vortex pinning can be increased by making the individual crystallites (or grains) of the material smaller, thus increasing the surface area associated with grain boundaries, where vortices get pinned.
这是因为晶粒边界面积的比例，会随著晶粒的缩小而增加，而涡流就是固定在晶粒边界上。