Lanthanum hafnate

Lanthanum hafnate is a colorless ceramic material[2] with the La and Hf atoms arranged in a cubic lattice.

[3][4] The compound decomposes into its constituent oxides at 18 GPa.

[5] Oxygen vacancies in the base material give luminescence spanning across the visible light spectrum, with a peak near 460 nm.

[6] The luminescent properties can be fine-tuned by doping with various rare earth and group 4 metals;[7][8] for example, La2Hf2O7:Eu3+ nanoparticles exhibit a red photoluminescence or radioluminescence near 612 nm when exposed to ultraviolet or X-ray radiation.

[9] Bulk ceramics can obtained by combusting the elements in powder form, and then pressing and sintering the powder at 180 MPa and 1,850 °C (2,120 K; 3,360 °F) for 6 hours:[2] It may also be made by precipitating hafnium and lanthanum hydroxides from solution and then calcinating in air at 600–1,400 °C (873–1,673 K; 1,112–2,552 °F) for 3 hours:[3]