MECHANICAL PROPERTIES OF Cr-DLC LAYERS PREPARED BY HYBRID LASER TECHNOLOGY

Diamond like carbon (DLC) layers have excellent biological properties for use in medicine for coating implants, but poor adhesion to biomedical alloys. The adhesion can be improved by doping the DLC layer by chromium, as described in this article. Chromium doped diamond like carbon layers (Cr‑DLC) were deposited by hybrid deposition system using KrF excimer laser and magnetron sputtering. Carbon and chromium contents were determined by wavelength dispersive X-ray spectroscopy. Mechanical properties were studied by nanoindentation. Hardness and reduced Young's modulus reached 31.2 GPa and 271.5 GPa, respectively. Films adhesion was determined by scratch test and reached 19 N for titanium substrates. Good adhesion to biomedical alloys and high DLC hardness will help to progress in the field of implantology

BaTiO3 FILMS DEPOSITED ONTO TiNb AND Ti SUBSTRATES - AMOUNT AND STABILITY OF BARIUM

BaTiO3 films deposited onto TiNb and Ti substrates using hydrothermal synthesis method were studied in the presented work. These films are supposed to improve properties of bone implants due to their ferroelectric behaviour, because ferroelectrics induce improved bone formation. A great question is the chemical stability of the used material. It can be crucial for its biocompatibility and possible in vivo application. We studied chemical composition of prepared samples, especially concentration of Ba and Ti and trends of these concentrations stimulated by a solution saline action. The Ba and Ti concentrations were determined by XPS under ultra - high vacuum condition. The BaTiO3 films were investigated as received after the preparation procedure as well as after a long - time treatment in solution saline. Every sample was introduced to the solution saline at first for 1 and later for 3 weeks. Ti concentration almost does not change during our experiments while a meaningful Ba decrease is observed. Nevertheless, barium release seems to slow down with respect to the time of solution saline action. Stability of barium titanate films in a period of several months and an absolute amount of the released barium will be a subject of the next research

BaTiO3 FILMS DEPOSITED ONTO TiNb AND Ti SUBSTRATES - AMOUNT AND STABILITY OF BARIUM

BaTiO3 films deposited onto TiNb and Ti substrates using hydrothermal synthesis method were studied in the presented work. These films are supposed to improve properties of bone implants due to their ferroelectric behaviour, because ferroelectrics induce improved bone formation. A great question is the chemical stability of the used material. It can be crucial for its biocompatibility and possible in vivo application. We studied chemical composition of prepared samples, especially concentration of Ba and Ti and trends of these concentrations stimulated by a solution saline action. The Ba and Ti concentrations were determined by XPS under ultra - high vacuum condition. The BaTiO3 films were investigated as received after the preparation procedure as well as after a long - time treatment in solution saline. Every sample was introduced to the solution saline at first for 1 and later for 3 weeks. Ti concentration almost does not change during our experiments while a meaningful Ba decrease is observed. Nevertheless, barium release seems to slow down with respect to the time of solution saline action. Stability of barium titanate films in a period of several months and an absolute amount of the released barium will be a subject of the next research

PLD prepared bioactive BaTiO₃ films on TiNb implants

Abstract BaTiO₃ (BTO) layers were deposited by pulsed laser deposition (PLD) on TiNb, Pt/TiNb, Si (100), and fused silica substrates using various deposition conditions. Polycrystalline BTO with sizes of crystallites in the range from 90 nm to 160 nm was obtained at elevated substrate temperatures of (600 °C–700 °C). With increasing deposition temperature above 700 °C the formation of unwanted rutile phase prevented the growth of perovskite ferroelectric BTO. Concurrently, with decreasing substrate temperature below 500 °C, amorphous films were formed. Post-deposition annealing of the amorphous deposits allowed obtaining perovskite BTO. Using a very thin Pt interlayer between the BTO films and TiNb substrate enabled high-temperature growth of preferentially oriented BTO. Raman spectroscopy and electrical characterization indicated polar ferroelectric behaviour of the BTO films