Mechanical characteristics of the NaCl: Eu2+ crystal system

Yield strength of NaCl: Eu²⁺ monocrystals was studied as function of both the dopant concentration and the annealing parameters. Main attention was paid to the strengthening mechanisms induced by the presence of europium related second phases the structure of which was controlled by means of optical methods. Depending on the nature of the second phases and their crystallographic relations with the matrix, two strengthening phenomena have been evidenced: this related with the presence of penetrable and that related with inprenetrable second phase particles. As far as the former ones can be sheared along with the matrix, the later — are overcomed due to a looping mechanism resembling the behaviour of metal alloys with the fcc — type of structure.