Synthesis of Hf 1‐x , Zr x 0 ₂ (O< x <1) with Orthorhombic Symmetry

Three starting materials, Hf 1‐x Zr x O 2 (x =0.24, 0.50, 0.74), were prepared and treated at 600°C and 6 GPa for 30 min. X‐ray powder diffraction patterns of the products indicated only orthorhombic HfO 2 . The lattice parameters increased linearly as x approached 1 (ZrO 2 ); a continuous solid‐solution series was observed.