Publications by authors named "Simone Vadilonga"

4 Publications

  • Page 1 of 1

Single crystals of ferroelectric lithium niobate-tantalate LiNbTaO solid solutions for high-temperature sensor and actuator applications.

Acta Crystallogr B Struct Sci Cryst Eng Mater 2020 Dec 16;76(Pt 6):1071-1076. Epub 2020 Nov 16.

Universität Potsdam, Institut für Physik, Karl Liebknecht Str. 24-25, Potsdam, 14471, Germany.

Ferroelectric LiNbTaO solid solutions with various Nb/Ta ratio were grown from the melt by the Czochralski method. The exact composition of the grown crystals was determined by inductively coupled plasma atomic mass spectrometry. The dependence of the crystal composition on the composition of the initial melt was obtained and explained by a wide separation between the phase boundaries of the liquid and solid phases on the LiNbO-LiTaO phase diagram. Using high-resolution X-ray diffraction, the parameters a and c of a crystal unit cell were determined (LiNbTaO: a = 5.1574 Å and c = 13.8498 Å). Further, the Curie temperature T of the crystals was measured using the differential scanning calorimetry technique. T was found to depend on the composition of the crystals that allowed conditions for the monodomainization of the grown crystals to be defined (LiNbTaO: T = 1102°C; LiNbTaO: T = 794°C). Finally, the velocity of surface acoustic waves was determined by scanning electron microscopy and X-ray diffraction techniques (YZ-cut of a LiNbTaO crystal: V = 3440 m s).
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http://dx.doi.org/10.1107/S2052520620014390DOI Listing
December 2020

Pulse picker for synchrotron radiation driven by a surface acoustic wave: erratum.

Opt Lett 2018 06;43(11):2490

An erratum is presented to correct the typographical errors concerning the composition of the multilayer used in the experiment in Opt. Lett. 42, 1915.
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http://dx.doi.org/10.1364/OL.43.002490DOI Listing
June 2018

Pulse picker for synchrotron radiation driven by a surface acoustic wave.

Opt Lett 2017 May;42(10):1915-1918

A functional test for a pulse picker for synchrotron radiation was performed at Diamond Light Source. The purpose of a pulse picker is to select which pulse from the synchrotron hybrid-mode bunch pattern reaches the experiment. In the present work, the Bragg reflection on a Si/B4C multilayer was modified using surface acoustic wave (SAW) trains. Diffraction on the SAW alters the direction of the x rays and it can be used to modulate the intensity of the x rays that reach the experimental chamber. Using electronic modulation of the SAW amplitude, it is possible to obtain different scattering conditions for different x-ray pulses. To isolate the single bunch, the state of the SAW must be changed in the short time gap between the pulses. To achieve the necessary time resolution, the measurements have been performed in conical diffraction geometry. The achieved time resolution was 120 ns.
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http://dx.doi.org/10.1364/OL.42.001915DOI Listing
May 2017

Observation of sagittal X-ray diffraction by surface acoustic waves in Bragg geometry.

J Appl Crystallogr 2017 Apr 14;50(Pt 2):525-530. Epub 2017 Mar 14.

Helmholtz Zentrum Berlin für Materialien und Energie, Germany; Freie Universität Berlin, Germany.

X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (LaGaSiO) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasonic superlattice. Experimental results are compared with the corresponding theoretical model that exploits the kinematical diffraction theory. This experiment shows that the propagation of the surface acoustic waves creates a dynamical diffraction grating on the crystal surface, and this can be used for space-time modulation of an X-ray beam.
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http://dx.doi.org/10.1107/S1600576717002977DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5377346PMC
April 2017