XRD endstation: condensed matter systems

Transcription

1 XRD endstation: condensed matter systems Justine Schlappa SCS Instrument Beamline Scientist Hamburg, January 24, 2017

2 2 Outline Motivation Baseline XRD setup R&D setup Two-color operation and split&delay line Sample preparation

3 Motivation 3 Physics of comples materials is determined by different degrees of freedom (i.a. nuclear, charge, spin, orbital) and their interplay Charge, orbital and spin order in La 0.5 Sr 1.5 MnO 4 Phase diagramm of copperoxide superconductors H.Y. Hwang et al., Nature Materials 11, 103 (2012). C. W. M. Castleton and M. Altarelli, Phys. Rev. B 62, 1033 (2000). B. Keimer et al., Nature 518, 179 (2015).

4 Resonant x-ray diffraction 4 E m2 E m1 hω in hω out E g Laue condition: Spin order 0.6 (1-ε,0,0) (2ε,0,1) Charge order [100] = q [001] Schüssler-Langeheine & Schlappa et al. W.S. Lee et al., Nature Communications 3, 838 (2012).

5 5 Resonant inelastic x-ray scatttering (RIXS) L.J.P. Ament et al., Rev. Mod. Phys. 83, 705 (2011). J. Schlappa et al., Nature 485, 82 (2012). See also talk: Stefan Neppl

6 6 Baseline SCS setup: X-ray Resonant Diffraction (XRD) Solid samples Techniques: Spectroscopy and Diffraction Resonant x-ray diffraction Reflectivity X-ray absorption Resonant inelastic x-ray scattering (hrixs) Pump-probe experiments / Nonlinear studies/ Single-shot experiments Soft and tender x-ray range: 0.25 kev 3 kev Pump laser: UV / Optical / IR / THz

7 7 Resonances in the energy range: 250 3,000 ev K-edges L 2,3 -edges M 4,5 -edges Particularly: accessibility of structural reflections down to ~ 2 Å

8 Experimental setup: 8 User consortium Heisenber RIXS spectrometer SCS beamline See talk: Stefan Neppl XRD chamber

9 XRD sample environment: 9 UHV, solid samples Temperature range: K Sample motion: 6 degrees Detector motion: 1 degree (2θ) Planned for Q1, 2018 Cryostat Sample position Diodes Motion Range Resolution X ± 10 mm 0.05 µm Y ± 10 mm 0.05 µm Z ± 10 mm 0.05 µm Azimuth ± 180 deg 0.05 deg Flip ± 30 deg 0.05 deg Theta ± 180 deg 0.01 deg TwoTheta ± 180 deg 0.01 deg Detector arm

10 10 XRD experimental geometry: Sample transfer Beam stop Sample transfer system Laser in-coupling mirrors Variable laser wavelengths Flange with continouos rotation: 60 < 2θ < 150 Sample Diode Signal 2D detector hrixs spectrometer Mirror 1 Mirror 2 Laser collinear with XFEL Laser XFEL

11 XRD experimental geometry: 11 Sample 2D-det Diode Signal Sample Diode Signal 2D-det Laser M 1 M 2 THz M 1 M 2 XFEL XFEL Laser non-collinear with XFEL THz collinear with XFEL See talk: Robert Carley

12 12 R&D, B-field setup: See talk: James Moore Simple setup, easily adaptable for specific user requirements Special feature: pulsed magnet, fields up to 15 T Temperature range: K Field direction: initially vertical, later also horizontal Sample degrees of motion: X, Y, Z, θ Sample transfer system Planned for ms time B-field structure: time delay

13 13 Two-color SASE3 operation See talk: Svitozar Serkez Magnetic chicane Experiment K1 Optical delay K2 electron beam SASE relative delay SASE delay λ 1 < λ 2 Concept of optical X-ray split and delay device for SASE3 (by AlexanderYaroslavtsev) G Recombination of different grating reflection orders at the optical axis

14 Nonlinear studies: Time-resolved CARS Grating λ 1 0 th order 1 st order λ 1 pink Slit λ 1 mono Grating λ 1 0 th order 1 st order 1 st order λ 2 pink λ 1 pink Slit λ 1 mono 14 ω Pump ω Stokes ω Probe t ω Signal GS Ω Ω λ 1 pink λ 1 mono λ 2 pink λ 1 mono λ 1 pink t t t GS GS

15 15 User lab Possibility to determine the orientation of pre-oriented crystals. See talk: Carsten Deiter Are there further demands from users?, e.g.: alignment of crystals of unknown orientation (Laue setup) sample preparation??

16 16 Summary XRD setup for spectroscopy, resonant diffraction and RIXS Energy extends to tender x-rays: additional resonances + structural studies accessible Pump laser: tunable wavelengths ranging from THz to UV R&D setup for special requirements and for B-field studies Two-color operation and split&delay line: novel experimental opportunities at SASE 3 Sample preparation: user requirements?

17 17 Thank you! Acknowledgements: SCS group (WP-86) Sample environment (WP-79) Simulation of Photon fields (WP-72)