Optical and mechanical properties of far infrared transmitting glass–ceramics

We have studied the mechanical properties of a new family of infrared transmitting glass–ceramics based on the GeS2–Sb2S3–CsCl system. Cs-based crystals have been generated inside the glass matrix and the crystal size is controlled to be less than 100 nm in order to keep the transparency of the composite materials. The presence of crystals leads to significant increase of the fracture toughness and the critical load for crack initiation. The increases depend on the type and on the size of crystals. Other mechanical properties such as Young’s modulus, Shear modulus are much less sensitive to these crystals.