Short-range order in ZrBaF glasses studied with γ–γ perturbed angular correlation

The γ–γ perturbed angular correlation (PAC) technique probes the electric field gradient (EFG) at the site of the nucleus of a probe atom surrounded by other atoms of a solid. Due to the quick drop of the EFG with distance the PAC technique is particularly well suited to study the lattice vicinity of suitable PAC probe atoms in solids on a sub-nanometer scale. Here, it is employed to investigate the short-range order in amorphous ZrBaF glasses using 181Hf as a probe. The results show that long before standard characterisation techniques like X-ray diffraction measurements detect the onset of crystallisation, the PAC results indicate a short-range order and allow the identification of crystalline precursors already present in the amorphous state.