Sustainable tourism: Whale watching footprint in the Bahía de Banderas, México

We have investigated the switching properties of ferroelectric lead strontium titanate capacitors using epitaxial La0.5Sr0.5CoO3 electrodes to evaluate their potential for non-volatile memory applications. It is proposed that the good performance of the PST capacitors can be attributed to the high degree of orientation of the PST films in the "001" direction induced by the epitaxial LSCO film. Fatigue tests were also carried out systematically by varying the switching pulse width with a fixed duty cycle and with a fixed switching period. A gradual increase followed by an abrupt increase of the fatigue rate was observed with the increase of the switching pulse width. Field-induced defect diffusion was used to explain the results. Copyright " Taylor & Francis Group, LLC.",,,,,,"10.1080/00150190903000765",,,"http://hdl.handle.net/20.500.12104/44888","http://www.scopus.com/inward/record.url?eid=2-s2.0-77955896899&partnerID=40&md5=327ba8e98e05f6d677323998cd376ca2",,,,,,"1 PART 2",,"Ferroelectrics",,"13

Switching properties of the Pt/PST/LSCO/STO ferroelectric heterostructure

We have investigated the switching properties of ferroelectric lead strontium titanate capacitors using epitaxial La0.5Sr0.5CoO3 electrodes to evaluate their potential for non-volatile memory applications. It is proposed that the good performance of the PST capacitors can be attributed to the high degree of orientation of the PST films in the «001» direction induced by the epitaxial LSCO film. Fatigue tests were also carried out systematically by varying the switching pulse width with a fixed duty cycle and with a fixed switching period. A gradual increase followed by an abrupt increase of the fatigue rate was observed with the increase of the switching pulse width. Field-induced defect diffusion was used to explain the results. Copyright © Taylor & Francis Group, LLC

Multi-wavelength images detector for micro-cathodoluminescence analysis

A novel instrument capable of collecting the entire cathodoluminescence emission spectrum simultaneously with SEM scanning is presented in this work. The cathodoluminescence produced in a standard scanning electron microscope is collected and analyzed. The electronic signal used by the microscope to trigger the electron raster and produce an image is also used by the spectrograph to synchronize spectrum acquisition. At each point in the sample the complete spectrum is acquired. All the data are recorded and saved in an electronic file. With this information it is possible to reconstruct panchromatic and/or monochromatic images of the sample and correlate its optical properties with its microstructure. Instead of an elliptical mirror to collect the light in the conventional CL system, a single optical fiber is used. This new way of acquiring light permits a reduction in the work distance (down to 5 mm) in the microscope, thus achieving a better spatial resolution. Another advantage of this arrangement is that we can simultaneously use other detection modes such as backscattered electrons, x-rays etc. Examples showed here illustrate the capabilities of the instrument

A novel and high yield synthesis of CdSe nanowires

CdSe nanowires (CdSe-NWs) at large scale were obtained through a simple and clean method. The reaction was carried out without complexing agents which often facilitate the preferential nanostructure growth. In this work, CdSe-NWs with lineal and zigzag shape around 40 and 130 nm in diameter with a wurtzite-type structure were synthesized. Quantitative EDX analysis indicated the stoichiometric formation of CdSe, while both HRTEM and HAADF-STEM analysis ruled out the presence of other phases such as CdO or nanotubes formation, respectively. Diameter and length of the nanowires varied with the reaction time and temperature. This synthesis method makes the nanostructures purification process easier and also is non-toxic and its high conversion make it an efficient method for obtaining CdSe-NWs

Surface phenomena involved in the formation of Co nanoparticles on amorphous Carbon and SiO₂ deposited by magnetron sputtering

High-pressure DC magnetron sputtering was used for the deposition of cobalt on amorphous carbon (a-C) and SiO. Deposition conditions, substrate surface morphology and annealing parameters are investigated in order to promote the synthesis of large arrays of nanoparticles, with regular size and shape. Uniformly distributed Co nanoparticles a few nanometers in size were formed under annealing at 700°C in H. Particle nucleation and growth are discussed based on X-ray photoelectron spectroscopy, transmission and scanning electron microscopy and kinetic Monte Carlo modeling (KMC). © Springer-Verlag 2010