Which size of impurity atom, smaller impurity atom or larger impurity atom, when located near a dislocation, will nullify some of the compressive strain of a dislocation in a crystal? Why?

Smaller impurity atom will nullify some of the compressive strain of a dislocation in a crystal. Because, smaller impurity atoms located near a dislocation creates tensile strain on atoms around it thereby partially nullifying compressive strain at the dislocation.