Publications by Camila Bacellar Cases Da Silveira

Tailoring p-Type Behavior in ZnO Quantum Dots through Enhanced Sol–Gel Synthesis: Mechanistic Insights into Zinc Vacancies

Jacques-Edouard Moser, Andrea Cannizzo, Etienne Christophe Socie, Camila Bacellar Cases Da Silveira, Victoria Kabanova

The synthesis and control of properties of p-type ZnO is crucial for a variety of optoelectronic and spintronic applications; however, it remains challenging due to the control of intrinsic midgap (defect) states. In this study, we demonstrate a synthetic ...

2024

Ultrafast carrier dynamics and insights in defect mechanism of p-type colloidal ZnO QDs

Jacques-Edouard Moser, Andrea Cannizzo, Etienne Christophe Socie, Camila Bacellar Cases Da Silveira, Victoria Kabanova

In this study, we place a strong emphasis on understanding the ultrafast dynamics of carrier recombination pathways in p-type ZnO, especially in the midgap region. Synthesizing and controlling the properties of p-type ZnO remains a pivotal yet challenging ...

SPIE2024

Separation of kinetic rate orders in extreme ultraviolet transient grating spectroscopy

Majed Chergui, Giulia Fulvia Mancini, Serhii Polishchuk, Oliviero Cannelli, Michele Puppin, Camila Bacellar Cases Da Silveira, Rebecca Ann Ingle, Hugo Jean Baptiste Marroux

We present an extreme ultraviolet (EUV) transient grating (TG) experiment of the spinel Co3O4 compound using tuneable incident energies across the Co M-2,M-3-edge and a 395 nm probe pulse, detecting both the first and the second diffraction orders (SDOs). ...

IOP Publishing2024

Deconvolution of the X-ray absorption spectrum of trans-1,3-butadiene with resonant Auger spectroscopy

Majed Chergui, Luca Longetti, Thomas Roland Barillot, Camila Bacellar Cases Da Silveira, Ludmila Maria Diniz Leroy

High-resolution carbon K-edge X-ray photoelectron, X-ray absorption, non-resonant and resonant Auger spectra are presented of gas phase trans-1,3-butadiene alongside a detailed theoretical analysis utilising nuclear ensemble approaches and vibronic models ...

Royal Soc Chemistry2024

A multi-reservoir extruder for time-resolved serial protein crystallography and compound screening at X-ray free-electron lasers

Camila Bacellar Cases Da Silveira, Christoph Bostedt

Serial crystallography at X-ray free-electron lasers (XFELs) permits the determination of radiation-damage free static as well as time-resolved protein structures at room temperature. Efficient sample delivery is a key factor for such experiments. Here, we ...

Nature Portfolio2023

Jahn-Teller effects in initial and final states: high-resolution X-ray absorption, photoelectron and Auger spectroscopy of allene

Majed Chergui, Luca Longetti, Thomas Roland Barillot, Camila Bacellar Cases Da Silveira, Rebecca Ann Ingle, Daniel Hollas, Ludmila Maria Diniz Leroy

Carbon K-edge resonant Auger spectra of gas-phase allene following excitation of the pre-edge 1s -> pi* transitions are presented and analysed with the support of EOM-CCSD/cc-pVTZ calculations. X-Ray absorption (XAS), X-ray photoelectron (XPS), valence ban ...

ROYAL SOC CHEMISTRY2023

Ultrafast Energy Transfer from Photoexcited Tryptophan to the Haem in Cytochrome c

Majed Chergui, Giulia Fulvia Mancini, Dominik Kinschel, Oliviero Cannelli, Camila Bacellar Cases Da Silveira, Rebecca Ann Ingle, Jérémy Raymond Jean Maurice Rouxel, Yang Zhao

: We report femtosecond Fe K-edge absorption (XAS) and nonresonant X-ray emission (XES) spectra of ferric cytochrome C (Cyt c) upon excitation of the haem (>300 nm) or mixed excitation of the haem and tryptophan (

2023

Carbon K-edge x-ray emission spectroscopy of gas phase ethylenic molecules

Majed Chergui, Luca Longetti, Thomas Roland Barillot, Camila Bacellar Cases Da Silveira, Rebecca Ann Ingle

We report on the C K-edge x-ray absorption spectra and the resonant (RXES) and non-resonant (NXES) x-ray emission spectra of ethylene, allene and butadiene in the gas phase. The RXES and NXES show clear differences for the different molecules. Overall both ...

IOP Publishing2022

Hard X-ray helical dichroism of disordered molecular media

Majed Chergui, Jérôme Lacour, Christian David, Giulia Fulvia Mancini, Malte Oppermann, Dominik Kinschel, Oliviero Cannelli, Camila Bacellar Cases Da Silveira

Chirality is a structural property of molecules lacking mirror symmetry that has strong implications in diverse fields, ranging from life sciences to materials science. Chirality-sensitive spectroscopic methods, such as circular dichroism, exhibit weak sig ...

Nature Publishing Group2022

Ultrafast X-ray Spectroscopy of Haem Proteins

Majed Chergui, Camila Bacellar Cases Da Silveira

In this article we revisit our recent picosecond and femtosecond X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) experiments, probing the ultrafast electronic and geometric evolution of photoexcited haem proteins, namely ferrous N ...

SWISS CHEMICAL SOC2022

Charging and ion ejection dynamics of large helium nanodroplets exposed to intense femtosecond soft X-ray pulses

Daniela Rupp, Camila Bacellar Cases Da Silveira, Christoph Bostedt

Ion ejection from charged helium nanodroplets exposed to intense femtosecond soft X-ray pulses is studied by single-pulse ion time-of-flight (TOF) spectroscopy in coincidence with small-angle X-ray scattering. Scattering images encode the droplet size and ...

SPRINGER HEIDELBERG2021

Femtosecond X-ray spectroscopy of haem proteins

Majed Chergui, Giulia Fulvia Mancini, Dominik Kinschel, Boris Sorokin, Oliviero Cannelli, Camila Bacellar Cases Da Silveira

We discuss our recently reported femtosecond (fs) X-ray emission spectroscopy results on the ligand dissociation and recombination in nitrosylmyoglobin (MbNO) in the context of previous studies on ferrous haem proteins. We also present a preliminary accoun ...

ROYAL SOC CHEMISTRY2021

X-ray absorption linear dichroism at the Ti K-edge of rutile (001) TiO2 single crystal

Majed Chergui, Giulia Fulvia Mancini, Thomas Charles Henry Rossi, Dominik Kinschel, Oliviero Cannelli, Camila Bacellar Cases Da Silveira, Jérémy Raymond Jean Maurice Rouxel

X-ray absorption linear dichroism of rutile TiO2 at the Ti K-edge provides information about the electronic states involved in the pre-edge transitions. Here, linear dichroism with high energy resolution is analyzed in combination with ab initio finite dif ...

INT UNION CRYSTALLOGRAPHY2020

Angular Momentum in Rotating Superfluid Droplets

Camila Bacellar Cases Da Silveira, Christoph Bostedt

The angular momentum of rotating superfluid droplets originates from quantized vortices and capillary waves, the interplay between which remains to be uncovered. Here, the rotation of isolated submicrometer superfluid He-4 droplets is studied by ultrafast ...

AMER PHYSICAL SOC2020

Femtosecond X-ray emission study of the spin cross-over dynamics in haem proteins

Majed Chergui, Giulia Fulvia Mancini, Dominik Kinschel, James Michael Budarz, Boris Sorokin, Oliviero Cannelli, Camila Bacellar Cases Da Silveira, Jérémy Raymond Jean Maurice Rouxel

In haemoglobin the change from the low-spin (LS) hexacoordinated haem to the high spin (HS, S = 2) pentacoordinated domed deoxy-myoglobin (deoxyMb) form upon ligand detachment from the haem and the reverse process upon ligand binding are what ultimately dr ...

Nature Research2020

Spin cascade and doming in ferric hemes: Femtosecond X-ray absorption and X-ray emission studies

Majed Chergui, Wojciech Gawelda, Christopher Alexander Arrell, Frederico Alves Lima, Giulia Fulvia Mancini, Dominik Kinschel, Oliviero Cannelli, Camila Bacellar Cases Da Silveira, Rebecca Ann Ingle, Jérémy Raymond Jean Maurice Rouxel, Samuel Menzi

The structure-function relationship is at the heart of biology, and major protein deformations are correlated to specific functions. For ferrous heme proteins, doming is associated with the respiratory function in hemoglobin and myoglobins. Cytochrome c (C ...

National Academy of Sciences2020

Taking a snapshot of the triplet excited state of an OLED organometallic luminophore using X-rays

Andrea Cannizzo, Martin Beck, Giulia Fulvia Mancini, Camila Bacellar Cases Da Silveira, Samuel Menzi, Victoria Kabanova

OLED technology beyond small or expensive devices requires light-emitters, luminophores, based on earth-abundant elements. Understanding and experimental verification of charge transfer in luminophores are needed for this development. An organometallic mul ...

Nature Publishing Group2020

A compact and cost-effective hard X-ray free-electron laser driven by a high-brightness and low-energy electron beam

Lukas Stingelin, Majed Chergui, Paul Beaud, Thomas Schietinger, Christopher Alexander Arrell, Thomas Schmidt, Leonid Rivkin, Christoph Peter Hauri, Giulia Fulvia Mancini, Rasmus Ischebeck, Eugenio Ferrari, Camila Bacellar Cases Da Silveira, Mike Seidel, Paolo Craievich, Sven Reiche

We present the first lasing results of SwissFEL, a hard X-ray free-electron laser (FEL) that recently came into operation at the Paul Scherrer Institute in Switzerland. SwissFEL is a very stable, compact and cost-effective X-ray FEL facility driven by a lo ...

Nature Publishing Group2020

X-ray absorption linear dichroism at the Ti K edge of anatase TiO2 single crystals

Majed Chergui, Giulia Fulvia Mancini, Thomas Charles Henry Rossi, Dominik Kinschel, Oliviero Cannelli, Camila Bacellar Cases Da Silveira, Jérémy Raymond Jean Maurice Rouxel

Anatase TiO2 (a-TiO2) exhibits a strong x-ray absorption linear dichroism in the pre-edge, the XANES and the EXAFS at the titanium K edge. In the pre-edge region, the behavior of the A1-A3 and B peaks originating from the 1s - 3d transitions is due to the ...

2019

Toward time-resolved laser T-jump/X-ray probe spectroscopy in aqueous solutions

Majed Chergui, Giulia Fulvia Mancini, Dominik Kinschel, Benjamin Bauer, Oliviero Cannelli, Camila Bacellar Cases Da Silveira, Rebecca Ann Ingle

Most chemical and biochemical reactions in nature and in industrial processes are driven by thermal effects that bring the reactants above the energy barrier for reaction. In aqueous solutions, this process can also be triggered by the laser driven tempera ...

2019