Preparation of delafossite CuFeO2 thin films by rf-sputtering on conventional glass substrate

CuFeO2 CuFeO2 is a delafossite-type compound and is a well known p-type semiconductor. The growth of delafossite CuFeO2 thin films on conventional glass substrate by radio-frequency sputtering is reported. The deposition, performed at room temperature leads to an amorphous phase with extremely low roughness and high density. The films consisted of a well crystallized delafossite CuFeO2 after heat treatment at 450 °C in inert atmosphere. The electrical conductivity of the film was 1 mS/cm. The direct optical band gap was estimated to be 2 eV

Preparation and characterization of the defect–conductivity relationship of Ga-doped ZnO thin films deposited by nonreactive radio-frequency–magnetron sputtering

Ga-doped ZnO (ZnO:Ga) thin films were prepared by radio-frequency–magnetron sputtering on conventional glass substrates at room temperature. The structural, electrical, and optical properties of these films as a function of argon pressure and film thicknesses were studied. All the films crystallized with the hexagonal wurtzite structure. The x-ray diffraction studies show that the ZnO:Ga films are highly oriented with their crystallographic c-axis perpendicular to the substrate. We discuss a methodology of using a “standardized platform” for comparison of samples deposited at different pressures, which provides an insight into the defect–resistivity relationship of each sample with respect to their microstructure. After the first annealing, the electrical properties of the films are dependent on the atmosphere used during postdeposition annealing treatment. A resistivity of 2.5 × 10−3 Ω · cm was obtained after vacuum annealing, and the films became an insulator after air annealing. The reproducibility of this treatment was verified. The average transmittance of all ZnO:Ga thin films is more than 85% in the visible range

Elaboration and characterization of Fe1–xO thin films sputter deposited from magnetite target

Majority of the authors report elaboration of iron oxide thin films by reactive magnetron sputtering from an iron target with Ar–O2 gas mixture. Instead of using the reactive sputtering of a metallic target we report here the preparation of Fe1–xOthin films, directly sputtered froma magnetite target in a pure argon gas flow with a bias power applied. This oxide is generally obtained at very low partial oxygen pressure and high temperature.We showed that bias sputtering which can be controlled very easily can lead to reducing conditions during deposition of oxide thin film on simple glass substrates. The proportion of wustite was directly adjusted bymodifying the power of the substrate polarization. Atomic force microscopy was used to observe these nanostructured layers. Mössbauer measurements and electrical properties versus bias polarization and annealing temperature are also reported

Determination of modified figure of merit validity for thermoelectric thin films with heat transfer model: Case of CuCrO2:Mg deposited on fused silica

Thermoelectric performance of a material is determined using a figure of merit (FOM) determined as ZT (ZT = σS2T/κ where σ is the electrical conductivity, S is the Seebeck coefficient, κ is the thermal conductivity, and T is the temperature). In the case of a thin film, it is normal in the first approach to consider calculating the FOM by using the thermal conductivity of the film. However, both the thermal influence of the substrate and the emissivity of the film must also be taken into account. In the present work, the heat transfer model is used in order to study the influence of the thermal conductivity, the thickness, and the emissivity of the film on the thermal gradient of the stack (substrate + thin film). The limits of these three parameters are determined in order to have the temperature variation due to the presence of the film compared to the substrate alone that remains less than 1%. Under these limits, the thermal conductivity of the substrate can be taken into account instead of the thermal conductivity of the thin film, and a modified FOM (Z’T) can be calculated. The present study leads to the determination of the validity of modified ZT. In the case of CuCrO2:Mg thin films, the model shows that the use of Z’T is valid. The calculated value of Z’T with the measured Seebeck coefficient and the electrical conductivity as a function of the temperature for 100 nm thick films and the temperature dependent thermal conductivity taken from the literature reached 0.02 at 210 °C. A thermoelectric module made with this material showed 10.6 nW when 220 °C is applied at the hot side

Developmental Trajectories in Siblings of Children with Autism: Cognition and Language from 4 Months to 7 Years

We compared the cognitive and language development at 4, 14, 24, 36, 54 months, and 7 years of siblings of children with autism (SIBS-A) to that of siblings of children with typical development (SIBS-TD) using growth curve analyses. At 7 years, 40% of the SIBS-A, compared to 16% of SIBS-TD, were identified with cognitive, language and/or academic difficulties, identified using direct tests and/or parental reports. This sub-group was identified as SIBS-A-broad phenotype (BP). Results indicated that early language scores (14–54 months), but not cognitive scores of SIBS-A-BP and SIBS-A-nonBP were significantly lower compared to the language scores of SIBS-TD, and that the rate of development was also significantly different, thus pinpointing language as a major area of difficulty for SIBS-A during the preschool years

Registro de movimientos oculares con el eye tracker Mobile eye XG

93 p.Debido a su importancia en la investigación sobre lo que sucede en el cerebro, el estudio sobre el sistema visual humano se ha especializado cada vez más para indagar sobre la influencia de los movimientos oculares en la percepción durante la observación. Con el fin de acceder a este tipo de procesos se ha diseñado un conjunto de herramientas que permiten hacer un seguimiento a los movimientos oculares, conocidos como eye trackers. Este libro tiene como objetivo aportar elementos para la planeación, el diseño y la ejecución de investigaciones que incluya el uso de eye trackers, en particular del eye tracker Mobile eye XG. Esta es una de las primeras revisiones en español que recopila información sobre los movimientos oculares. Contiene una descripción sobre el eye tracker Mobile eye XG y otros dispositivos; una revisión sobre la visión humana y los movimientos oculares; una reseña acerca de los determinantes cognoscitivos de los movimientos oculares; una aproximación a las condiciones para el diseño, la ejecución y el análisis de datos de las investigaciones con esta herramienta y una revisión sobre sus campos de aplicación.Technological advances in recent decades have made eye trackers, especially glasses, an important tool in the field of cognitive, emotional, and social neurosciences, due to the relationship that exists between visual behavior and neuronal processes. This has facilitated the study of a significant number of psychological processes, including perception, emotions, social cognition, decision making, attention, and literacy, among others. Eye trackers have been applied to research a wide range of human activities, including web page and application design and market studies, the visual behavior of drivers and athletes, human-computer interactions, simulations for military training, and as a support for the clinical diagnosis of personality disorders and neurological conditions. This book aims to provide elements for the planning, design, and execution of research that includes the use of eye trackers, in particular the Mobile Eye-XG eye tracker. This is one of the first reviews in Spanish that collects information on eye movements. The study contains a description of the Mobile Eye-XG eye tracker and other devices; a review of human vision and eye movements; a review of the cognitive determinants of eye movements; an exploration of the conditions that determine the design, execution, and data analysis of research that uses this tool, as well as a review of its fields of application.Introducción Parte 1. Descripción del eye tracker Mobile eye XG Parte 2. Visión humana y movimientos oculares Parte 3. Neurobiología de los movimientos oculares Parte 4. Determinantes cognoscitivos de las fijaciones y de los movimientos oculares Parte 5. Condiciones para el diseño y el registro de estudios con el eye tracker Mobile eye XG Parte 6. Análisis y representación gráfica de los datos Parte 7. Condiciones para el reporte de investigación Parte 8. Aplicaciones del eye tracking Referencias Anexo

Thin Films and Fine Powders of Ferrites : Materials for Magneto-Optical Recording Media

In the near future, the magneto-optical (MO) recording will require materials having high MO effects at short wavelengths (400-500 nm). Ferrites, especially garnets, but also spinel ferrites have highly advantageous MO properties in this spectrum and also have very stable structural and chemical properties. The present paper evaluates their used as MO media, in comparison with the rare-earth transition metals alloys and the metallic multilayers

Microstructural characterization of CoMnFeO

CoMnFeO4 thin films are stable materials useful to study the influence of radio-frequency sputtering experimental conditions, on the microstructure of oxide films. From various techniques of electronic microscopy, gas adsorption techniques and ellipsometry measurements, it was shown that such oxides films prepared with 0.5 Pa sputtering argon pressure and 5 cm target–substrate distance are very dense. On the other hand, the samples obtained under higher pressure and/or longer distance, are microporous. This porosity is mainly due to shadowing and energetic effects of sputtered particles. According to different characterization techniques, a simple model is proposed to describe the microstructure of the films studied