Short-and medium-range structure synergistically control fracture toughness of densified aluminoborate glasses

摘要: Methods to improve the fracture toughness of oxide glasses are needed since low fracture toughness is a major bottleneck for their applications. To overcome this, it is critically important to investigate the effect of both short-and medium-range structural features on fracture toughness. Recent work reported a record-high fracture toughness for a bulk lithium aluminoborate glass subjected to hot compression. Here, we further explore the structural origin of this high fracture toughness by subjecting different alkali aluminoborate glasses to hot compression. Through a combination of x-ray total scattering experiments and atomistic simulations, we find that hot compression causes significant changes to both the short-and medium-range order structure of the glasses, eg, increased coordination numbers (CNs) of network forming species and decreased average size of ring-type structures. To this end, we reveal positive …