ORCID Profile
0000-0003-4348-4714
Current Organisations
Universidade de São Paulo
,
Universitas Gadjah Mada
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Publisher: Elsevier BV
Date: 10-2011
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 12-2013
Publisher: American Physical Society (APS)
Date: 10-08-2011
Publisher: Elsevier BV
Date: 10-2012
Publisher: Geological Society of America
Date: 2009
Publisher: Springer Science and Business Media LLC
Date: 12-2018
Publisher: American Physical Society (APS)
Date: 08-11-2010
Publisher: American Geophysical Union (AGU)
Date: 03-2019
DOI: 10.1029/2018JB016865
Publisher: American Geophysical Union (AGU)
Date: 10-11-2007
DOI: 10.1029/2007JB004963
Publisher: AIP Publishing
Date: 05-06-2014
DOI: 10.1063/1.4878675
Abstract: The optical conductivity (σ1) of SrTiO3 for various vacancies has been systematically studied using a combination of ultraviolet-vacuum ultraviolet reflectivity and spectroscopic ellipsometry. For cation (Ti) vacancies, σ1 shows large spectral weight transfer over a wide range of energy from as high as 35 eV to as low as 0.5 eV and the presence of mid-gap states, suggesting that strong correlations play an important role. Meanwhile, for anion (O) vacancies, σ1 shows changes from 7.4 eV up to 35 eV.
Publisher: American Chemical Society (ACS)
Date: 31-08-2011
DOI: 10.1021/NN202910T
Abstract: We demonstrated a novel method to obtain charge neutral quasi-free-standing graphene on SiC (0001) from the buffer layer using fluorine from a molecular source, fluorinated fullerene (C(60)F(48)). The intercalated product is stable under ambient conditions and resistant to elevated temperatures of up to 1200 °C. Scanning tunneling microscopy and spectroscopy measurements are performed for the first time on such quasi-free-standing graphene to elucidate changes in the electronic and structural properties of both the graphene and interfacial layer. Novel structures due to a highly localized perturbation caused by the presence of adsorbed fluorine were produced in the intercalation process and investigated. Photoemission spectroscopy is used to confirm these electronic and structural changes.
Publisher: Springer Science and Business Media LLC
Date: 22-01-2018
Publisher: Wiley
Date: 23-04-2018
Abstract: Magnetotactic bacteria are a multi-phyletic group of bacteria that synthesize membrane-bound magnetic minerals. Understanding the preservation of these minerals in various environments (e.g., with varying oxygen concentrations and iron supply) is important for understanding their role as carriers of primary magnetizations in sediments and sedimentary rocks. Here we present X-ray near edge structure (XANES) spectra for Fe in magnetotactic bacteria s les from recent sediments to assess surface oxidation and crystal structure changes in bacterial magnetite during early burial. Our results are compared with a XANES spectrum of cultivated Magnetofaba australis s les, and with magnetic properties, and indicate that oxidation of magnetite to maghemite increases with depth in the sediment due to longer exposure to molecular oxygen. These results are relevant to understanding magnetic signatures carried by magnetofossils in oxic sediments and sedimentary rocks of different ages.
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 07-2018
Publisher: Springer Science and Business Media LLC
Date: 20-07-2016
DOI: 10.1038/SREP29838
Abstract: The South Asian Monson (SAM) is one of the most intense climatic elements yet its initiation and variations are not well established. Dating the deposits of SAM wind-driven currents in IODP cores from the Mal es yields an age of 12. 9 Ma indicating an abrupt SAM onset, over a short period of 300 kyrs. This coincided with the Indian Ocean Oxygen Minimum Zone expansion as revealed by geochemical tracers and the onset of upwelling reflected by the sediment’s content of particulate organic matter. A weaker ‘proto-monsoon’ existed between 12.9 and 25 Ma, as mirrored by the sedimentary signature of dust influx. Abrupt SAM initiation favors a strong influence of climate in addition to the tectonic control, and we propose that the post Miocene Climate Optimum cooling, together with increased continentalization and establishment of the bipolar ocean circulation, i.e. the beginning of the modern world, shifted the monsoon over a threshold towards the modern system.
Publisher: Springer Science and Business Media LLC
Date: 18-02-2019
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 12-2018
Publisher: Elsevier BV
Date: 2016
Publisher: IOP Publishing
Date: 09-2021
Publisher: American Physical Society (APS)
Date: 03-06-2013
Publisher: Elsevier BV
Date: 11-2014
Publisher: Proceedings of the National Academy of Sciences
Date: 22-02-2016
Abstract: New information from the ANDRILL-2A drill core and a complementary ice sheet modeling study show that polar climate and Antarctic ice sheet (AIS) margins were highly dynamic during the early to mid-Miocene. Changes in extent of the AIS inferred by these studies suggest that high southern latitudes were sensitive to relatively small changes in atmospheric CO 2 (between 280 and 500 ppm). Importantly, reconstructions through intervals of peak warmth indicate that the AIS retreated beyond its terrestrial margin under atmospheric CO 2 conditions that were similar to those projected for the coming centuries.
Publisher: American Geophysical Union (AGU)
Date: 02-03-2007
DOI: 10.1029/2006JB004655
Publisher: The Royal Society
Date: 28-10-2012
Abstract: We report room-temperature ferromagnetism (FM) in highly conducting, transparent anatase Ti 1− x Ta x O 2 ( x ∼0.05) thin films grown by pulsed laser deposition on LaAlO 3 substrates. Rutherford backscattering spectrometry (RBS), X-ray diffraction, proton-induced X-ray emission, X-ray absorption spectroscopy (XAS) and time-of-flight secondary-ion mass spectrometry indicated negligible magnetic contaminants in the films. The presence of FM with concomitant large carrier densities was determined by a combination of superconducting quantum interference device magnetometry, electrical transport measurements, soft X-ray magnetic circular dichroism (SXMCD), XAS and optical magnetic circular dichroism, and was supported by first-principles calculations. SXMCD and XAS measurements revealed a 90 per cent contribution to FM from the Ti ions, and a 10 per cent contribution from the O ions. RBS/channelling measurements show complete Ta substitution in the Ti sites, though carrier activation was only 50 per cent at 5 per cent Ta concentration, implying compensation by cationic defects. The role of the Ti vacancy ( V Ti ) and Ti 3+ was studied via XAS and X-ray photoemission spectroscopy, respectively. It was found that, in films with strong FM, the V Ti signal was strong while the Ti 3+ signal was absent. We propose (in the absence of any obvious exchange mechanisms) that the localized magnetic moments, V Ti sites, are ferromagnetically ordered by itinerant carriers. Cationic-defect-induced magnetism is an alternative route to FM in wide-band-gap semiconducting oxides without any magnetic elements.
Publisher: Elsevier BV
Date: 10-2022
Publisher: American Geophysical Union (AGU)
Date: 03-2019
DOI: 10.1029/2018JB016576
Publisher: International Ocean Discovery Program
Date: 07-03-2016
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 03-2008
Location: No location found
Location: Netherlands
No related grants have been discovered for Luigi Jovane.