The solid state route that implies the direct interaction

Table 1.
Experimental conditions of high-energy ball milling of the ZrO2–GeO2 and HfO2–GeO2 mixtures.Atmosphere and pressureAir, 1 atmJar?s volume50 cm3Total ball weight32 gBall diameter10 mmBall and jar materialYttria stabilized zirconia (YSZ)Mass charge6.4 gAcceleration300 m/s2Full-size tableTable optionsView in workspaceDownload as CSV
2.3. High-temperature treatment of oxide mixtures
The initial and mechanically activated powder mixtures were heated in air in the diffractometer chamber with CCT 031374 constant heating rate of 30 °С/min in the 25–1200 °C temperature range with sample exposure at 900, 1000, 1100, and 1200 °C. Dwell time at each temperature was 5 min. In addition, mechanically treated powder mixtures were calcined in the muffle furnace at 1200 °C with exposure to air for 6 h.
2.4. Characterization
The morphology and elemental composition of products were examined by S-3400N and ТМ-1000 (Hitachi, Japan) scanning electron microscopes coupled with OXFORD INCA Energy 200 (Oxford Instruments, UK) energy dispersive spectrometer and SwiftED-TM (Hitachi, Japan) software.