The following experimental techniques and setups are available to users in this beamline. To learn more about the techniques’ limitations and requirements (sample, environment, etc.) contact the beamline coordinator before submitting your proposal.
Photoluminescence (PL) in the vacuum ultraviolet energy range is used to investigate the region of the optical band gap and valence band in crystalline solids. Using the PL technique, it is possible to describe the valence band, the band gap length, the position of energy levels and understanding their role during the optical process. This information may allow the development of new and customized materials for specific applications, such as biomarkers, radiation detectors, lasers, light emitting diodes (LED), phosphors for illumination devices, energy-harvesting materials, etc.
Setup: The PL setup is composed by two main modes of detection. For the first one, the excitation mode, an optical fiber is positioned in angle with the sample and the fiber cable is coupled in a photomultiplier (PMT) for integrating the light emitted by the sample after the interaction with the synchrotron radiation. This signal gives information of the excitation of the sample in a specific range of energy. The second setup is the emission one. It is similar to the first and the difference is that the optical fiber is now coupled to a spectrometer (200 – 900 nm), allowing the retrieval of the profile of the emission spectra after excitation at specific energies. The flexible setup of the detection/control of the beamline allows different complementary setups: (i) monitor the emission intensity as a function of both emission and excitation energies; (ii) time-resolved studies (for persistent and fluorescent samples). Total Electron Yield (TEY) has also been used in these studies to monitor the behavior of the sample in absorption.
Recent publications using this setup:
- Segreto, A.A. Machado, W. Araujo, V. Teixeira, “Delayed light emission of Tetraphenyl-butadiene excited by liquid argon scintillation light. Current status and future plans” Journal of Instrumentation, v. 11, n. 02, p. C02010, 2016. doi:10.1088/1748-0221/11/02/C02010
- C. Teixeira, L.C.V. Rodrigues, D. Galante, M.V.S. Rezende, “Effect of lithium excess on the LiAl5O8:Eu luminescent properties under VUV excitation” Optical Materials Express, v. 6, n. 9, p. 2871-2878, 2016. doi: 10.1364/OME.6.002871
- C.S. Pedroso, J.M. Carvalho, L.C.V. Rodrigues, J. Höslä, H.F. Brito, “Rapid and Energy Saving Microwave-Assisted Solid-State Synthesis of Pr3+, Eu3+ or Tb3+ Doped Lu2O3 Persistent Luminescence Materials” ACS Applied Materials & Interfaces, 2016. doi: 10.1021/acsami.6b04683
- S. Bezerra, M.E.G. Valerio, “Structural and optical study of CaF2 nanoparticles produced by a microwave-assisted hydrothermal method”. Physica B: Condensed Matter, v. 501, p. 106-112, 2016. doi: 10.1016/j.physb.2016.08.025
SAMPLE IRRADIATION AND MASS SPECTROMETRY
The beamline can be used as a light source with unique characteristics. This mode is specially interesting to cover the wavelengths below 280 nm (UVB), deeper on the UV (down to 4nm), which is present, for instance, on space conditions. In addition to producing monochromatic light, the beamline can operate in white-beam mode (full spectrum) and pink-beam mode (white-beam with the low-pass gas filter, to introduce a cutoff on the higher energies). These modes can be used to simulate the Solar radiation in space to test materials for the aerospace industry (specially polymers), and also as sources of light for astrophysics, astrochemistry in gas and solid phases, and to probe the resistance of biomolecules and microorganisms under space or planetary simulations, for astrobiology.
Setup: in this mode, the beamline normally operates with a standard chamber for the irradiation of the material. If needed, different measurement systems can be mounted to monitor the sample in situ and in real time, such as mass spectrometers (QMS, ToF) or other spectroscopic techniques (UV-Vis and Raman). Customized setups can be arranged if feasible, with prior contact with the beamline staff.
Recent publications using this setup:
- M. Betancourt, L.H. Coutinho, R. B. Bernini, C.E.V. Moura, A B. Rocha, G. G. B. Souza. “VUV and soft x-ray ionization of a plant volatile: Vanillin (C8H8O3). The Journal of chemical physics, v. 144, n. 11, p. 114305, 2016. doi:10.1063/1.4944084.
- C. Abrevaya, I.G. Paulino-Lima, D. Galante, F. Rodrigues, P.J.D. Mauas, E. Cortón, C.A.S. Lage. “Comparative survival analysis of Deinococcus radiodurans and the Haloarchaea Natrialba magadii and Haloferax volcanii exposed to vacuum ultraviolet irradiation. Astrobiology, v. 11, n. 10, p. 1034-1040, 2011. doi:10.1089/ast.2011.0607.
- S. Arruda, A. Medina, J.N. Sousa, L.A.V. Mendes, R.R.T. Marinho, F.V. Prudente, “Communication: Protonation process of formic acid from the ionization and fragmentation of dimers induced by synchrotron radiation in the valence region”. The Journal of chemical physics, v. 144, n. 14, p. 141101, 2016. doi: 10.1063/1.4945807