Synthesis of advanced materials by pulsed-laser deposition

Advanced thin film materials with giant dielectric permittivities up to ≈ 10000 were produced by pulsed-laser deposition. Composite targets of barium titanate (BaTiO3) and polytetrafluorethylene (PTFE) were ablated with 248 nm KrF-laser radiation in Ar atmosphere. The synthesized films have a complex microstructure and contain product species which are formed during the pulsed-laser ablation / deposition process. The dielectric permittivities of films exhibit pronounced dispersion for frequencies higher than 10 kHz. Strong dependencies of the film permittivity on target composition, layer thickness, ambient gas pressure and relative humidity are revealed. The large dielectric permittivity of these film materials may be attributed to space-charge polarization phenomena. Films deposited from the same targets in oxygen atmosphere have much lower dielectric permittivity (ετ'≈ 30).

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