0000000001156470

AUTHOR

P. François

showing 2 related works from this author

Phase transitions in i-butylammonium halogenoantimonate(III) and bismuthate(III) crystals

1997

Abstract Differential scanning calorimetry, dielectric, thermal expansion, infrared and preliminary X-ray diffraction studies on i-butylammonium halogenoantimonate(III) and bismuthate(III) crystals are reported. All crystals: (i-C4H9NH3)2BiCl5, (i-C4H9NH3)2SbBr5, (i-C4H9NH3)3BiCl6, (i-C4H9NH3)3Bi2Br9, (i-C4H9NH3)3Sb2Br9, show one or more structural phase transitions of first order type. The values of the transition entropies suggest that the most of the phase transitions are of the order-disorder type. The infrared studies confirmed the contribution of the i-butylammonium cations in the phase transition mechanism.

DiffractionPhase transitionInfraredChemistryOrganic ChemistryBismuthateDielectricThermal expansionAnalytical ChemistryInorganic ChemistryCrystallographychemistry.chemical_compoundDifferential scanning calorimetryFourier transform infrared spectroscopySpectroscopyJournal of Molecular Structure
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Gaia-ESO Survey: Global properties of clusters Trumpler 14 and 16 in the Carina nebula

2017

Aims: We present the first extensive spectroscopic study of the global population in star clusters Trumpler 16, Trumpler 14, and Collinder 232 in the Carina nebula, using data from the Gaia-ESO Survey, down to solar-mass stars. Methods: In addition to the standard homogeneous survey data reduction, a special processing was applied here because of the bright nebulosity surrounding Carina stars. Results: We find about 400 good candidate members ranging from OB types down to slightly subsolar masses. About 100 heavily reddened early-type Carina members found here were previously unrecognized or poorly classified, including two candidate O stars and several candidate Herbig Ae/Be stars. Their l…

astro-ph.SROpen clusters and associations: individual: Carina nebulaastro-ph.GAExtinction (astronomy)PopulationFOS: Physical sciencesAstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsOpen clusters and associations: individual: Trumpler 1401 natural sciencesindividual: Trumpler 16 [Open clusters and associations]Open clusters and associations: individual: Trumpler 16individual: Trumpler 14 [Open clusters and associations]Stars: early-typeearly-type [Stars]pre-main sequence [Stars]QB4600103 physical sciencesAstrophysics::Solar and Stellar Astrophysicseducation010303 astronomy & astrophysicsComputingMilieux_MISCELLANEOUSAstrophysics::Galaxy AstrophysicsSolar and Stellar Astrophysics (astro-ph.SR)O-type starLine (formation)[PHYS]Physics [physics]PhysicsNebulaeducation.field_of_studyOpen clusters and associations: Individual: Carina nebula; Open clusters and associations: Individual: Trumpler 14; Open clusters and associations: Individual: Trumpler 16; Stars: Early-type; Stars: Pre-main sequence; Astronomy and Astrophysics; Space and Planetary Science010308 nuclear & particles physicsStar formationAstronomy and AstrophysicsAstrophysics - Astrophysics of GalaxiesStarsStar clusterAstrophysics - Solar and Stellar AstrophysicsSpace and Planetary ScienceAstrophysics of Galaxies (astro-ph.GA)Stars: pre-main sequenceAstrophysics::Earth and Planetary Astrophysicsindividual: Carina nebula [Open clusters and associations][PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
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