The structural correlation and mechanical properties in amorphous silicon nitride under densification

► A correlation between the BADs and the fraction of structural units ► The density can be expressed via the fraction of structural units. ► The sample with high density contains a remarkable number of big voids. ► A number of PTEs link to each other by common N atoms to create a poly-PTE. ► The strain hardening and softening become more pronounced with increasing density.