Solid State Nuclear Magnetic Resonance and X-ray Diffraction Line Profile Analysis of heavily deformed fluorite

The effect of high-energy ball milling on calcium fluoride was studied by X-ray Diffraction (XRD) Line Profile Analysis (LPA) and Solid State Nuclear Magnetic Resonance (NMR) spin–lattice relaxation. The latter technique is especially useful not only to detect the nonhomogeneous effects of the early stages of mechanical grinding, but is also sensitive to the defect structure of the ball milled powders. When supported by Solid State NMR, XRD LPA unveils fine details of the milling effects on fluorite, in terms of increasing dislocation density and progressive refinement of the crystalline size down to the nanoscale.

► Calcium fluoride samples were ball-milled for several milling times. ► Short milling times produce inhomogeneous nanocrystalline powders. ► Solid State Nuclear Magnetic Resonance (NMR) relaxation analysis was performed. ► NMR and powder X-ray Diffraction (XRD) data obtained were modelled. ► The microstructure development due to milling is followed by both NMR and XRD.