Proposal for a beamline: ENERGY AND POLARIZATION DEPENDENT SCATTERING

1. Proposal for a beamline: ENERGY AND POLARIZATION DEPENDENT SCATTERING Joaquín García Ruiz Instituto de Ciencia de Materiales de Aragón Universidad de Zaragoza – C.S.I.C., 50009 Zaragoza (Spain) E-mail: & jgr@ unizar.es

2. This proposal was presented in the Phase II, which included SINGLE CRYSTAL DIFFRACTION (Chemical Crystallography & Material Science) ENERGY AND POLARIZATION DEPENDING SCATTERING * Similar Energy Range – High Energy ( 5 – 35 KeV) * High flux at sample ( 1013 photons) * Analogous experimental design (4/6 circles goniometers) * High and variable focalisation (50-200 mm) With the aim to optimize financial support

3. How the proposal has been originated? SINGLE CRYSTAL DIFFRACTION (Chemical Crystallography & Material Science) ENERGY AND POLARIZATION DEPENDING SCATTERING Experiments: 1- Energy dependent scattering: Resonant x-ray scattering, Diffraction Anomalous Fine Structure (DAFS), MAD. 2- Magnetic scattering with x-rays: resonant and non-resonant, site selected X-ray Magnetic Circular Dichroism, x-ray magnetic reflectivity. 3- ¿Surface diffraction?

4. Outlook of the presentation • 0.- Make use of all the singular properties of SR, High flux, • energy dependence and polarization. • 1.-Energy and Polarization Dependent Scattering (EPDS) • Magnetic Scattering with x-rays • Resonant X-ray Scattering • Diffraction Anomalous Fine Structure and MADS • X-ray magnetic reflectivity and site resolved XMCD • 3.- Beam line – Technical Description • Competitive European beam lines • Beam line typical requirements • Source • Optic and Experimental hutches

5. Energy and polarization dependent scattering(EPDS) elastic scattering cross-section The scattering factor by one atom can be written as: f(E)= f0 + fmagn + f’(E) +if”(E), f0is the Thomson scattering amplitude, proportional to the atomic number fmagn is the non-resonant magnetic scattering amplitude f’(E) and f”(E) are the resonant terms of the scattering amplitude.

6. Examples of experiments using EPDS: • Magneticscatteringwith x-rays • Resonant X-rayScattering • ATS, Charge and orbital ordering, multipolar ordering • AnomalousScattering • DAFS, DANES, MAD • Site-selective XMCD

7. Magnetic scattering with x-rays • Why? • Can be used for investigations of submillimiter-sized single crystals • Can be used for compounds with neutron opaque elements • Can be used for studies of magnetic surfaces and interfaces • Resonant magnetic scattering probe local magnetism • Solving magnetic structures • Angular and polarization dependence of resonant and non-resonant scattering • cross-sections •  directions of the magnetic moments and separation of spin and orbital moments • Scattering amplitudes  Magnitude of the ordered magnetic moment

8. s-s s-p Non-resonantmagneticscattering: Experimental separation of Spin and Orbital moments in KCuF3 (Caciuffo et al. PRB 65 174425 (2002)) By measuring the intensity ratios between the s-s and s-p polarization channels for different magnetic reflections as a function of the scattering vector Q, it is possible calculate the ratio of orbital L(Q) and spin S(Q) moments by Magnetic moment II (110) plane L and S collinear Azimuthal dependence of antiferromagnetic reflection (005) taken at 11 K

9. TOPICS: • Transition-metal oxides (cuprates, manganites, etc) • Rare-earth magnetism • Strongly correlated electron systems • Spin-density and charge-density waves • Surface magnetism • Magnetic ordering in compounds non-suitable for neutron diffractionFrustrated magnetism in low dimensional systems • Induced magnetism in non-magnetic elements

10. Scattering k' k  ' Resonant x-ray scattering The tensorial character of the atomic scattering factor is difficult to be resolved for intense permitted reflections. It can be approached as scalar. This is the approach generally used in the structural DAFS studies of materials. The tensorial description becomes noticeable when the Thomson scattering is very small. Therefore, most of the RXS studies deal with either very weak allowed reflections or the so-called “forbidden” reflections, which are systematically extinct by symmetry.

11. 1- To solve electronic differences between crystallographic sites occurring in a structural phase transition. The so-called charge ordering (CO) transitions. Example: Structural origin of the CO transition in Nd0.5Sr0.5MnO3 Energy dependence of the intensity of the (3 0 0) and (0 3 0) reflections in the s-s' channel and the (0 5/2 0) reflection in the s-p' channel at different azimuthal angles. Checkerboard ordering of Mn+3.42-Mn+3.58 were deduced.

12. 2- “forbidden” or ATS (anisotropy of the tensor of susceptibility) reflections Example 3: Glide-plane forbidden reflections in LaMnO3 The origin of these two independent reflections is related to two different non-zero non-diagonal elements of the scattering tensor. RXS can not be described as a OO of eg electrons

13. 3-To disentangling multipole resonances and led to the detection of phase transitions characterized by order parameters of exotic symmetry. In these cases, a full x-ray polarization analysis as the sample is rotated around the scattering vector permits to identify the occurrence of higher multipole (quadrupole, octupole, hexadecapole, etc) electronic orderings competing with the dipolar coupling and to subtle interference effects among them. Example : Vanadium magnetoelectric multipoles in V2O3 Fits of the observed intensities as a function of the azimuthal angle in the reflections (3,0,-2)m and (1,1,1)m for the ss’ and sp’ polarizations channels. The amplitude is a coherent sum of dipole-quadrupole (E1-E2) and pure quadupole (E2-E2) resonance events. Estimates of the V anapole (E1-E2) and V octupole (E2-E2) can be separated to within a few percent.

14. Topics ■ Orbital order and orbital transitions in single crystal samples of transition metal oxides (with and without cooperative Jahn-Teller order) ■ Orbital frustration and orbital liquids in systems with quasi-degenerated orbital degrees of freedom. ■ Electronic crystals: Charge order, charge density modulations and molecular orbitals in oxides ■ Spin state transitions in cobaltites and other transition metal oxides ■ Magnetoelectric or multiferroic crystals (“single phase”) ■ Phase separation, charge stripe phases and inhomogeneous states in complex transition metal oxides ■ Low dimensional oxide systems and spin ladders ■ Correlation effects at oxide interfaces ■ Multilayer and composite multiferroics (“multi-phase) ■ The effect of light polarisation and its application in extreme sample conditions is a promissing new field.

15. Diffraction Anomalous Fine Structure (DAFS, DANES) and Multiwavelength Anomalous Diffraction (MAD) DAFS provides both the advantages of x-ray diffraction and absorption, however it is more than the addition of absorption and diffraction, it is simultaneously a site and chemically selective probe. The site/spatial selectivity of DAFS helps to solve the difficulty by selecting individual sites. Ga environment in GaAsN/GaAs and InGaAsN/GaAs quantum wells Scatt. geometry GIDAFS experiments have been combined to GIMAD h anom. scans MAD, FGa and FAs

16. EDAFS, exp ad refin. EXAFS oscillations the effect of capping on strain evolution is elucidated, showing an increasing deviation from the elastic biaxial deformation, with increasing AlN cap thickness. The influence of the substrate on the QDs morphology is also put in evidence, for SiC substrates the QDs are more relaxed than for AlN substrates. It is shown that the combination of MAD and DAFS provides a sensitivity to cap thickness as low as 2 ML.

17. Topics DANES Valence determination Site separation Magnetic DANES DAFS Site separation of EXAFS spectra Local structure of dopants Magnetic DAFS Polarized DAFS RXMS MAD MAD phasing for macromolecular structures Element selective diffraction Contrast between neighbouring elements Cation localization in complex substituted samples Atomic selectivity for modulated structure analysis

18. Contributors • Grazia Proietti***Universidad de Zaragoza DAFS; MAD; GIDAFS • Jose Luis Garcia-Muñoz ICMAB, charge-orbital ordering • Jesus A. Blanco*** Universidad de Oviedo, phase transitions and multipole orderings • Joaquín García Ruiz, Gloria Subías, Javier Blasco ICMA, charge-orbital ordering • Claudio Mazzoli (Politécnico de Milán), magnetic scattering • Gianluca Ciatto (Soleil) • Hubert Renevier (Grenoble) • Potential users • -XAS community can benefit of these techniques • Nanoscience • Magnetism • -Materials Science • -Surface Science

19. Recent results: 1- Fe-based high Tc superconductors. S. Nandi et al, PRB 79, 100407 (2009); J. Herrero-Martin et al PRB 80, 134411(2009); M. G. Kim et al PRB 82, 180412 (2010) 2- Multiferroics. Determination of the moments orientation by RMXS in Mn1-xCoxMnO4. J. Herrero et al.; Charge ordering in LuFe2O4, Lafuerza et al., submitted PRL (2014) 3- Angular Anisotropy in valence states. Determination of atomic multipoles and chiral properties in a-Fe2O3, BiFeO3. J. A. Blanco et al, PRB 88 094437 (2013), PRB 83 054427 (2011), JPSJ 83 013706 (2014) 4- Stripe-ordering in High-Tc Cu superconductors. Charge Correlations in YBa2Cu3O6 Superconductors Probed by RXS. C. Mazzoli et al PRL18, 187001 (2013); Long-range Inconmensurate charge fluctuations in YBCO.C. Mazzoli et al Science 337, 821 (2012) 5- Ge-Si quantum dots. InGaN/GaN Core shell Nanowires and Ge/Si QDs; Proietti et al., Europhys. Lett. (2011) 6- Interfacial magnetism. Transition metal multilayers by hard x-ray magnetic reflectivity, J. I. Martín (Oviedo), C. Quirós et al, Surf. Science 606, 936 (2012).

20. Active groups • Zaragoza • Mixed valence oxides, J. García, G. Subías, J. Blasco (ICMA) • Semiconductors and intermetallics, M. G. Proietti, J. I. Arnaudas (INA e ICMA) • Nanomagnets and amorphous magnetic alloys, F. Bartolome, J. Bartolome. (ICMA) • Barcelona • Cobaltites, nickelates, etc , J. L. Garcia Muñoz, ICMAB • Charge ordering in manganites, S. Wall ICFO • Resonant scattering, Fe- based high-Tc superconductors, multiferroics, J. Herrero- Martin, • Manuel Valvidares ALBA • Oviedo • Chiral properties, atomic multipoles. J.A. Blanco, A. Rodriguez-Fernandez, Univ. de Oviedo • XRMS studies in ferrimagnetic rare earth, J. I. Martin, C. Quirós, Univ. de Oviedo • Bilbao • -Ferrites, Maria Luisa Fernandez Gubieda UPV • Madrid • -Magnetoresistance, metal-insulator phase transitions, J.L. Alonso ICMM

21. European Facilities Landscape

22. Beamline for ENERGY AND POLARIZATION DEPENDENT SCATTERING • Typical requirements • Brilliance: ~1019 at 6 keV, • (ph/sec/mrad2/mm2/0.1%bw) ~10 times smaller above 20 keV • Photon energy (keV): 5 – 35 • Energy resolution (DE/E): < 10-4 • Efficient Harmonic rejection: < 10-4 • Photon flux at sample: ~1013 at 6 keV, • (ph/sec//mm20.1%bw/300mA) ~100 times smaller above 20 keV • Small beam sizes (mm2): routinely 150 x 50 (+ microfocus) • Position stability (mm): ±10 • Variable linear and circular polarization

23. Source: IVU21 undulator 3rd armonic 5.3-9 KeV armonic > 9 for E>25 KeV

24. Optics and experimental hutches

25. EPDS: 6 circles diffractometer Sample to detector distance: > 500 mm Mu: ±3°, accuracy 0.001°, encoder resolution 0.0001° Gamma (detector): -40° ¸ +190°, accuracy 0.001°, encoder resolution 0.0001° Delta (detector): -100° ¸ +280°, accuracy 0.001°, encoder resolution 0.0001° Omega: ±180°, accuracy 0.001°, encoder resolution 0.0001° Chi: ±7°, accuracy 0.001°, encoder resolution 0.0001° Phi: range +/- 180°, accuracy 0.001°, encoder resolution 0.0001° XYZ translation stage load capacity: > 500 kg Sphere of confusion: 30 mm with 500 kg load Detector arm sphere of confusion: < 100 mm with 40 kg load Especial requirements Set of crystals for polarization analysis: each absorption edge needs one different crystal. Phase retarder (two diamond phase plates): 1. Quarter-wave plate condition for circular polarization -Fast switching between left and right circular polarization -Compensation of intensity differences by using 2 phase plates in series 2. Half-wave plate condition for linear polarization -Continuous rotation of plane of linear polarization

26. Detectors EPDS needs point detection as long as polarisation analysis on weak signals. Given the energy range to cover, both fast APD detectors and scintillators have to be considered as monitor and detectors. Linear detection systems are the best choice for DAFS/GI-DAFS experiments. The required detector arm can allocate all of them rather easily on a user friendly switching device. Software Standard and commercial Estimated cost:About 5000 K€

27. Final Comments 1- It seems that the singular properties of materials as high-Tc superconductors, magnetoresistance, multiferroics, etc… come from very subtle changes in the structure and/or the electronic states that conventional techniques have been unable to discriminate. RXS, DAFS and magnetic scattering techniques could provide the key answer to resolve these questions as it has been recently done with some topics (Verwey transition). 2- Since the requirements of this beam line are very similar to the “Surface-interphase diffraction beam line” and in order to optimize the possible funds, I would propose to consider the possibility of joining the two proposals.

28. Acknowledgments Claudio Mazzoli, Politécnico de Milán, Italia Gianluca Ciatto, Synchrotron SOLEIL - Beamline SIRIUS, France M. Grazia Proietti, Universidad de Zaragoza, Spain Gloria Subías Peruga, ICMA, CSIC-Universidad de Zaragoza, Spain