Study of sprayed coatings and compound materials by impedance spectroscopy

The impedance spectroscopy (IS) and electrical equivalent circuit method were used to investigate both electric and structural properties of materials. The analysis of a hydroxyapatite SPS sprayed layer allowed the determination of the degree of amorphousness. The difference between impedance spectra of dry and moist samples allowed the comparison of samples in terms of their porosity. Results of measurements of barium titanate nanoceramics were presented. The content of amorphous and crystalline phases was found to be dependent on the ceramic grain size. The Curie effect was observed in the crystalline phase which proved that it preserved its ferroelectric properties in spite of nanometre-sized grains.