Search results for "Curie"
showing 10 items of 110 documents
The effects of the additive of Eu ions on elastic and electric properties of BaTiO3ceramics
2016
ABSTRACTThe BaTiO3 and BaTiO3+X%wt.Eu2O3 (X = 1, 2, 3) ceramics were prepared by a solid phase reaction. The structural and morphology studies were carried out by means of an X-ray diffraction technique and scanning electron microscopy, respectively. Elastic moduli were determined with the use of an ultrasonic method. The dielectric permittivity (ϵ′) and tanδ as a function of composition and temperature were investigated. The increasing concentration of Eu ions leads to a slight shift of the Curie temperature and changes the characteristics of ϵ′ and tanδ. The structural, mechanical and dielectric properties of the BTEX ceramics were discussed in terms of microstructure and dopants contents.
Nitrogen broadening of SF6 transitions in the nu3 band
2001
Abstract Nitrogen induced pressure-broadened halfwidths of a number of ν3 transitions of SF6 are calculated using the complex Robert–Bonamy (CRB) formalism. The calculations are made at 200, 250, 296 and 350 K and the temperature dependence of the halfwidths are determined. The intermolecular potential is taken as a sum of the leading electrostatic and Lennard-Jones [6] , [7] , [8] , [9] , [10] , [11] , [12] atom–atom components. The dynamics of the collision process are correct to second order in time. The calculated halfwidths are used to simulate the ν3 spectrum, which is compared to a simulation made using the HITRAN96 halfwidths and measurements made at the Universite Pierre et Marie C…
Editorial: Legumes for global food security
2020
descripción no proporcionada por scopus
High-spin polarization of Heusler alloys
2006
Fermi surface of a half-metal compound with cubic Fm–3m symmetry: Heusler alloy or double perovskite.The inset shows the spin resolved density of state for a CCFA Heusler compound. ( This illustration appears on the cover of the print edition. ) This cluster issue of Journal of Physics D: Applied Physics is devoted to magnetic Heusler alloys. This class of materials is currently considered to contain the most attractive half-metallic ferromagnets due to their high Curie temperatures and their structural relation to conventional semiconductors. The first compound to be identified as a half-metallic ferromagnet, by de Groot et al back in 1983, was the half-Heusler alloy NiMnSb. After a period…
Off-stoichiometry in Co2FeSi thin films sputtered from stoichiometric targets revealed by nuclear magnetic resonance
2009
Co2FeSi is predicted to be a half-metallic ferromagnet with an extraordinary high magnetic moment and Curie temperature. However, a low tunnel magneto-resistance ratio, a lower spin polarization and a lower magnetic moment were experimentally observed in thin film samples. Consequently, thin Co2FeSi films of different groups were studied using spin-echo nuclear magnetic resonance (NMR). NMR probes the local hyperfine fields of the active atoms, which strongly depend on the local environment. NMR is thus able to reveal the next neighbouring shells of the Co-59 nuclei in the Co2FeSi thin films. As expected, our NMR study shows the main resonance line corresponding to Co-59 nuclei in the L2(1)…
Magnetic and structural study of (Fe1−Co )62 Nb8B30 bulk amorphous alloys
2004
Abstract The electric and magnetic properties of rapidly quenched (Fe 1− x Co x ) 62 Nb 8 B 30 bulk metallic glasses were studied with x =0, 0.33 and 0.50. The Curie temperature in the amorphous state was found to be about 245 °C for the Co-free alloy, 290 °C for x =0.33 and 201 °C for x =0.50, while the crystallization temperature is varying within 15° only around 600 °C. The change in T C correlates with the change in Mossbauer parameters. An interesting flattening effect of annealing on the hysteresis loop was observed which increases with the Co content. The resistivity could not be improved above 152 μΩ cm, which limits the high frequency applications of these alloys.
Artificial intelligence for image-guided prostate brachytherapy procedures
2020
Radiotherapy procedures aim at exposing cancer cells to ionizing radiation. Permanently implanting radioactive sources near to the cancer cells is a typical technique to cure early-stage prostate cancer. It involves image acquisition of the patient, delineating the target volumes and organs at risk on different medical images, treatment planning, image-guided radioactive seed delivery, and post-implant evaluation. Artificial intelligence-based medical image analysis can benefit radiotherapy procedures. It can help to facilitate and improve the efficiency of the procedures by automatically segmenting target organs and extrapolating clinically relevant information. However, manual delineation…
Towards asteroseismology of core-collapse supernovae with gravitational-wave observations – I. Cowling approximation
2017
Gravitational waves from core-collapse supernovae are produced by the excitation of different oscillation modes in the protoneutron star (PNS) and its surroundings, including the shock. In this work we study the relationship between the post-bounce oscillation spectrum of the PNS–shock system and the characteristic frequencies observed in gravitational-wave signals from core-collapse simulations. This is a fundamental first step in order to develop a procedure to infer astrophysical parameters of the PNS formed in core-collapse supernovae. Our method combines information from the oscillation spectrum of the PNS, obtained through linear perturbation analysis in general relativity of a backgr…
« Te vir laudabilis illum defensore necnon et vos honerati que curas puplicas agitis adsidue… Regards sur la vitalité civique des cités post-romaines…
2021
While the classical civic organization is said to have disappeared in the West after 500, defensores, honorati, curies and curiales are still attested in Frankish Gaul until the 9th century, which has been discussed for a long time. A re-examination of the available evidence infers the existence of curies in some twenty Gallic cities at least. According to the historiography, they didn’t govern cities anymore, but were the local partners of the count and the bishop. However, at their lower level, and probably with much diversity from one city to another, they had their own functions and real autonomy. They remained places of power, expression and distinction for local aristocracy and were i…
Half-metallic ferromagnetism with high magnetic moment and high Curie temperature in Co$_2$FeSi
2006
Co$_2$FeSi crystallizes in the ordered L2$_1$ structure as proved by X-ray diffraction and M\"o\ss bauer spectroscopy. The magnetic moment of Co$_2$FeSi was measured to be about $6\mu_B$ at 5K. Magnetic circular dichroism spectra excited by soft X-rays (XMCD) were taken to determine the element specific magnetic moments of Co and Fe. The Curie temperature was measured with different methods to be ($1100\pm20$)K. Co$_2$FeSi was found to be the Heusler compound as well as the half-metallic ferromagnet with the highest magnetic moment and Curie temperature.