Effect of Zr doping on the high-temperature stability of SiO₂ glass

A SiO₂–ZrO₂ glass was prepared by cold pressing and sintering, and the effect of ZrO₂ on the high-temperature stability of SiO₂ was studied. First-principle calculation based on density functional theory was applied to analyze the solution energies of Zr atom in ZrSiO₄ and SiO₂. The results show that Zr element can diffuse into SiO₂ lattice, and influence the SiO₂ structure in two ways, including introduction in the interstitial region and substituting a Si atom in SiO₂. The interstitial Zr breaks the nearest Si–O bond to form Zr–O and Zr–Si bonds, while the substitutional Zr has little influence on the SiO₂ network. The interfacial adhesion energy between the Zr-doped SiO₂ and the pure SiO₂ increases from 3.93 J/m² to 4.56 J/m² with the introduction of Zr atom, which is beneficial for improving the high-temperature stability of SiO₂ glass.