Advanced search
Start date
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

A versatile X-ray phase retarder for lock-in XMCD measurements

Full text
Poldi, Eduardo H. T. [1, 2] ; Escanhoela Jr, Carlos A. ; Fonseca Jr, Jairo ; Eleoterio, Marcos A. S. [3] ; dos Reis, Ricardo D. [3] ; Lang, Jonathan C. [4] ; Haskel, Daniel [4] ; Souza-Neto, Narcizo M. [3]
Total Authors: 8
[1] Brazilian Ctr Res Energy & Mat, Brazilian Synchrotron Light Lab, BR-13083970 Campinas, SP - Brazil
[2] Univ Estadual Campinas, Inst Phys Gleb Wataghin, BR-13083860 Campinas, SP - Brazil
[3] Fonseca Jr, Jr., Jairo, Escanhoela Jr, Jr., Carlos A., Brazilian Ctr Res Energy & Mat, Brazilian Synchrotron Light Lab, BR-13083970 Campinas, SP - Brazil
[4] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 - USA
Total Affiliations: 4
Document type: Journal article
Source: JOURNAL OF SYNCHROTRON RADIATION; v. 27, n. 5, p. 1247+, SEP 2020.
Web of Science Citations: 0

X-ray magnetic circular dichroism (XMCD) is a technique commonly used to probe magnetic properties of materials with element and orbital selectivity, which requires the use of circularly polarized (CP) X-rays. It is possible to accomplish XMCD experiments with fixed CP and alternating the magnetic field orientation, but most reliable data are obtained when alternating the magnetization orientation and the polarization between right and left helicities. A versatile strategy has been developed to perform XMCD experiments using a hard X-ray quarter-wave plate, at both polychromatic dispersive and conventional monochromatic optics, in combination with synchronous data acquisition. The switching frequency waveform is fed into a lock-in amplifier to detect and amplify the XMCD signal. The results on a reference sample demonstrate an improvement in data quality and acquisition time. The instrumentation successfully generated 98% of CP X-rays switching the beam helicity at 13 Hz, with the possibility of faster helicity switching once it is installed at the new Brazilian fourth-generation source, SIRIUS. (AU)

FAPESP's process: 14/26620-8 - X-ray 1/4 wave plate for magnetic dichroism
Grantee:Eduardo Henrique de Toledo Poldi
Support type: Scholarships in Brazil - Scientific Initiation
FAPESP's process: 13/22436-5 - Synchrotron Radiation techniques under extreme conditions
Grantee:Narcizo Marques de Souza Neto
Support type: Research Grants - Young Investigators Grants
Grantee:Carlos Augusto Escanhoela Júnior
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 14/05480-3 - Multi-user equipment approved in grant 2013/22436-5: facility for high pressure experiments
Grantee:Narcizo Marques de Souza Neto
Support type: Multi-user Equipment Program