1. Thermal Effusivity Investigations of Solid Thermoelectrics Using the Front Photopyroelectric DetectionCarmen Tripon, Dorin Dadarlat, Katalin Kovacs, Victor Petru Tosa, Mladen Franko, 2020, izvirni znanstveni članek Opis: The front photopyroelectric configuration (FPPE), making use of air as a coupling
fluid between the sample and sensor, was applied to measure the thermal effusivity of
some solid thermoelectric materials. The investigated samples were ZnO, CuCrO2,
Cu4Sn7S16,
TiS3
and two samples of high manganese silicide (HMS) thermoelectric
materials. Most of these materials are porous and consequently, the classical PPE
method, making use of standard coupling fluids between sensor and sample, cannot
be used due to the fact that the coupling fluid penetrates inside the sample and leads
to incorrect results. With this work we extend (to thermoelectric solids) the area of
application of a method, recently proposed by Salazar et al. (Measurement 121: 96,
2018). Experimentally, the thermal effusivity is obtained from a multi-parametric
fit of the phase of the FPPE signal as a function of the modulation frequency (with
sample’s thermal effusivity, thickness of the sensor-sample air gap and heat losses
by convection and radiation, as fitting parameters). It was demonstrated that, in some
particular cases, the three parameters are independent and consequently, the solution
of the fit is unique. Where possible, the obtained results have been compared with
data from the literature and good agreement was found. Ključne besede: Front photopyroelectric configuration (FPPE), Solid thermoelectrics, Thermal effusivity Objavljeno v RUNG: 02.05.2020; Ogledov: 3435; Prenosov: 0 Gradivo ima več datotek! Več... |
2. Spin and orbital configuration of metal phthalocyanine chains assembled on the Au(110) surfaceGargiani Pierluigi, Giorgio Rossi, Roberto Biagi, Valdis Corradini, Maddalena Pedio, Sara Fortuna, Arrigo Calzolari, Stefano Fabris, Julio Criginski Cezar, N. B. Brookes, Maria Grazia Betti, 2013, izvirni znanstveni članek Opis: The spin and orbital configuration of magnetic metal phthalocyanines (MPcs) deposited on metallic substrates are strongly influenced by the rehybridization of the molecular states with the underlying metal. FePc, CoPc, and CuPc isolated molecules are archetypal systems to investigate the interrelationship between magnetic moments and orbital symmetry after deposition on a metallic substrate. MPcs form long-range ordered chains self-assembled along the reconstructed channels of the Au(110) surface. X-ray magnetic circular dichroism from the L2,3 absorption edges of Fe, Co, and Cu shows that the orbital and spin configuration are strongly modified upon adsorption on the Au(110) surface if the orbitals responsible of the magnetic moment are involved in the interaction process. The magnetic moment for a single layer of molecular chains is completely quenched for the CoPc molecules, fully preserved for the CuPc and reduced for the FePc ones. The modified magnetic configuration is confined to the very interface layer, i.e., to the MPc molecules bound to the metal substrate up to the compact packing of the single layer. The different response can be rationalized in terms of the symmetry/orientation of the metal-ion d states interacting with the substrate states, as indicated by density functional theory calculations in agreement with experimental findings. Ključne besede: phthalocyanine, Au(110), gold, self-assembly, pattern, configuration, density functional theory, DFT, CuPc, FePc Objavljeno v RUNG: 12.10.2016; Ogledov: 5414; Prenosov: 0 Gradivo ima več datotek! Več... |