Investigation of the structural and microstructural properties of Gd3+-modified BaTiO3 ceramics

Structural and microstructural properties of lead-free BaBa1-xGdxTiO3 ceramics are investigated. The results confirm the formation of the ferroelectric phase, for all the cases, revealing a decrease in the unit-cell volume (V) with the increase of the gadolinium concentration, which can be associated to the difference between the ionic-radii of the involved ions (Gd3+ and Ba2+). A decrease in the average grain-size, with the increase of the Gd3+ content, was associated to the pinning effect (typical of rare-earths) due to the contribution of minor additional phase, which is not easily detectable by X-ray diffraction technique at very low dopant concentrations.