Study of nanomechanical properties of (1-y)BST-yMgO thin films

In the present study thin films of MgO - modified Ba0.6Sr0.4TiO3 (BST60/40) solid solution were prepared by the sol-gel-type chemical solution deposition method on stainless steel substrates. A multilayer spin-coating approach was utilized for the Ba0.6Sr0.4TiO3-MgO thin film deposition with subsequent thermal annealing at T=650-750°C. Dried BST60/40-MgO gel powders were studied with thermogravimetric and differential thermal analysis to determine their thermochemical properties. X-ray diffraction analysis was utilized for thin film characterization in terms of its phase composition and crystal structure. The influence of y=1, 3 and 5 mol.% MgO doping on nanomechanical properties of BST60/40 thin films was studied with nanoindentation. It was found that BST6040 thin films adopted the tetragonal P4mm (99) structure. The volume of the BST60/40 elementary cell, the average hardness as well as the mean value of the Young modulus decreased with an increase in amount of MgO.