Effect of Al2O3 nanocrystals on the structural and electrical studies of lithium titanate phosphate glass ceramic matrix

A series of lithium phosphate glass ceramics dispersed with Al2O3 nanocrystals were synthesized via high energy ball milling technique. The milling of Al2O3 powder at room temperature for different milling times is 0, 5, 10, 20, 30, 40, 50 and 60 h. The mean particle size distribution was measured using the Scherrer formula for a half width of the diffraction peaks vary from micrometers to ∼24 nm for the milling time at 40 h. The details of compositions chosen for the present study of investigation are given in the general formula: (100−x) [0.4Li2O-0.1TiO2-0.6P2O5]+x 40 h ball milled Al2O3 (where x=0, 2, 4, 6, 8, 10 and 12 mol% ) and labeled as LTPAx (where x is the mole% of 40 h ball milled Al2O3). The average crystallite size of Al2O3 nanoparticles was measured to be 22 nm by transmission electron microscopy (TEM) images, which is in good agreement with the crystallite size calculated from X-ray diffraction (XRD) (24 nm) measurements using Scherrer's formula. The frequency dependent conductivity was explained in the light of conducting nanocrystalline phases such as AlPO4, LiTi2(PO4)3, LiAl2P3O7 precipitated in the LTPA samples.