Substitutions of dual-ion Al3+/Mo6+ for Zr4+/V5+ in ZrV2O7 for realizing near-zero thermal expansion

Zr1-xAlxV2-xMoxO7 (0 x 0.9) is developed by the solid state method, and the near-zero thermal expansion is realized by adjusting the quantity of substitution of Al3+/Mo6+ for Zr4+/V5+ in ZrV2O7. For smaller x values (x 0.3), the samples remain the same cubic structure as that of ZrV2O7. The Coulomb interaction between (Al/Zr)- and (Mo/V)+ increases gradually with increasing the quantity of dual-ion substitution of Al3+/Mo6+ for Zr4+/V5+ in ZrV2O7, which reduces the fraction of the distortionless cubic structure in the sample. For x 0.7, the cubic structures could not be found. For Zr0.5Al0.5V1.5Mo0.5O7, near-zero thermal expansion is obtained in a temperature range from 425 to 750 K (-0.3910-6 K-1). The mechanism of low thermal expansion of Zr0.5Al0.5V1.5Mo0.5O7 could relate to the distortion of crystal structure due to partial substitution of Al3+/Mo6+ for Zr4+/V5+ in ZrV2O7 and the effect of the substitution on the unsubstituted lattice.