Doping of tantalum, niobium, and hafnium in a translucent ZrO2-SiO2 nanocrystalline glass-ceramic

•The ternary dopants enhanced the transformability of tetragonal ZrO2.•Lamella nanotwins were formed within many ZrO2 nanocrystallites.•No obvious segregation of dopants was detected at ZrO2 grain boundaries.•The dopants imparted a yellowish- or dark-brown color to the glass-ceramics.•Tetragonal and monoclinic ZrO2 were metastable in the thermal treatments.