Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userIn situ Auger electron spectroscopy of complex oxide surfaces grown by pulsed laser deposition
214
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The authors report in situ Auger electron spectroscopy (AES) of the surfaces of complex oxides thin films grown by pulsed laser deposition (PLD). The authors demonstrate the utility of the technique in studying chemical composition by collecting characteristic Auger spectra of elements from samples such as complex oxide thin films and single crystals as well as metal foils. In the case of thin films, AES studies can be performed with single unit cell precision by monitoring thickness during deposition with reflection high energy electron diffraction (RHEED). The authors address some of the challenges in achieving in situ and real time AES studies on complex oxide thin films grown by PLD. Sustained layer-by-layer PLD growth of a CaTiO3/LaMnO3 superlattice allows depth-resolved chemical composition analysis during the growth process. The evolution of the Auger spectra of the elements from individual layers were used to perform chemical analysis with monolayer-depth resolution.
rate research
Read More
To visualize the topography of thin oxide films during growth, thereby enabling to study its growth behavior quasi real-time, we have designed and integrated an atomic force microscope (AFM) in a pulsed laser deposition (PLD) vacuum setup. The AFM scanner and PLD target are integrated in a single support frame, combined with a fast sample transfer method, such that in-situ microscopy can be utilized after subsequent deposition pulses. The in-situ microscope can be operated from room temperature (RT) up to 700$^circ$C and at (process) pressures ranging from the vacuum base pressure of 10$^{-6}$ mbar up to 1 mbar, typical PLD conditions for the growth of oxide films. The performance of this instrument is demonstrated by resolving unit cell height surface steps and surface topography under typical oxide PLD growth conditions.
Cu2Ta4O12 (CTaO) thin films were successfully deposited on Si(100) substrates by pulsed-laser deposition technique. The crystalline structure and the surface morphology of the CTaO thin films were strongly affected by substrate temperature, oxygen pressure and target - substrate distance. In general during deposition of CTaO the formation of a Ta2O5 phase appeared, on which CTaO grew with different orientations. We report on the experimental set-up, details for film deposition and the film properties determined by SEM, EDX and XRD.
In this paper, we report the growth of NaxCoO2 thin films by pulsed-laser deposition (PLD). It is shown that the concentration of sodium is very sensitive to the substrate temperature and the target-substrate distance due to the evaporation of sodium during the deposition. alpha prime-phase Na0.75CoO2 and gamma- phase Na0.71CoO2 thin films can be obtained with different conditions. Correspondingly, the surface morphology of the films changes from flake-like to particle-like. The temperature dependence of resistivity for the films prepared with the optimal condition shows metallic behavior, consistent with the data of NaxCoO2 single crystals. This work demonstrates that PLD is a promising technique to get high quality NaxCoO2 thin films.
We report on how different cluster deposition regimes can be obtained and observed by in situ Scanning Tunneling Microscopy (STM) by exploiting deposition parameters in a pulsed laser deposition (PLD) process. Tungsten clusters were produced by nanosecond Pulsed Laser Ablation in Ar atmosphere at different pressures and deposited on Au(111) and HOPG surfaces. Deposition regimes including cluster deposition-diffusion-aggregation (DDA), cluster melting and coalescence and cluster implantation were observed, depending on background gas pressure and target-to-substrate distance which influence the kinetic energy of the ablated species. These parameters can thus be easily employed for surface modification by cluster bombardment, deposition of supported clusters and growth of films with different morphologies. The variation in cluster mobility on different substrates and its influence on aggregation and growth mechanisms has also been investigated.
Thin superconducting films of magnesium diboride (MgB2) with Tc approx 24K were prepared on various oxide substrates by pulsed laser deposition (PLD) followed by an in-situ anneal. A systematic study of the influence of various in-situ annealing parameters shows an optimum temperature of about 600C in a background of 0.7 atm. of Ar/4%H2 for layers consisting of a mixture of magnesium and boron. Contrary to ex-situ approaches (e.g. reacting boron films with magnesium vapor at 900C), these films are processed below the decomposition temperature of MgB2. This may prove enabling in the formation of multilayers, junctions, and epitaxial films in future work. Issues related to the improvement of these films and to the possible in-situ growth of MgB2 at elevated temperature are discussed.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
