Brillouin scattering: its application to the study of damage and amorphization

A brief review of Brillouin scattering is made emphasizing its advantages and disadvantages over conventional ultrasonic techniques. One of its advantages is that the elastic properties of very thin films (∼ 1μ) can be investigated. The authors have used this technique to study changes in shear elastic constants of materials irradiated with high energy ions. These particles only penetrate ∼ 1μ into the material but produce very high defect concentrations which, in certain cases, can lead to amorphization. In Nb3Ir and Zr3Al very large changes are observed before the onset of amorphization, while in Si the changes occur concomitantly with amorphization. The significance of the hardening observed in Zr3Al when it becomes amorphous will be discussed