Optimization of ball-to-powder weight ratio toward to highly transparent LaGdZr2O7 ceramics processing by solid reactive sintering

Highly transparent LaGdZr₂O₇ ceramics were fabricated by solid reactive sintering using the ball-milling mixed raw powder, and the transparency of samples can be significantly enhanced by optimizing the ball-to-powder weight ratio. The ratio effects on the evolution of morphology and particle size distribution of mixed powder, as well as the relative density and the in-line transmittance of obtained LaGdZr₂O₇ ceramics were investigated in detail. As the ratio increased above 24:1, the uniform and spherical-like particles became platy particles with bimodal particle size distribution (platy bimodal powder), while the relative density and transmittance of the LaGdZr₂O₇ ceramics were obviously improved. The highest in-line transmittance of 74.8% at 1100 nm, about 94% of the theoretical transmittance, can be achieved when milling ratio 27:1 was employed. Combined with the high refractive index (2.08 at 632.8 nm), high density (6.446 g/cm³) and high effective atomic number, the highly transparent LaGdZr₂O₇ ceramics obtained in this work can find potential applications in many areas such as optical lens and promising candidates for scintillator host, etc.