Journal of large-scale research facilities, 1, A5 (2015) http://dx.doi.org/10.17815/jlsrf-1-24 Published: 18.08.2015 SPODI: High resolution powder di�ractometer Heinz Maier-Leibnitz Zentrum Karlsruhe Institute of Technology Technische Universität München Instrument Scientists: - Markus Hoelzel, Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany, phone: +49(0) 89 289 14314, email: markus.hoelzel@frm2.tum.de - Anatoliy Senyshyn, Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany, phone: +49(0) 89 289 14316, email: anatoliy.senyshyn@frm2.tum.de - Oleksandr Dolotko, Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany, phone: +49(0) 89 289 14373, email: odolotko@frm2.tum.de Abstract: The high resolution powder di�ractometer SPODI (jointly operated by the Karlsruhe Insti- tute of Technology and the Technische Universität München) is designed for structure solution and Rietveld re�nement of crystal and magnetic structural parameters on polycrystalline powders. Instru- mental speci�cation (design, �exibility, peak shape, resolution etc.) as well as a variety of specialized sample environment equipment implemented for in-situ materials characterisation make the instru- ment attractive for studies of complex ordering phenomena. 1 Introduction The instrument is characterised by a very high monochromator take-o� angle of 155° (standard con- �guration). Optionally, a take-o� angle of 135° is available. The detector array consists of 80 3He position sensitive detector tubes (300 mm active height) with �xed Soller collimators of 10’ horizontal divergence. The multidetector of SPODI spans an angular range of 2θ = 160°. Each detector covers 2° corresponding to 160°/ 80 detectors. Therefore the data collection is performed via stepwise positioning of the detector array to obtain a di�raction pattern of the desired step width (typically 2°/ 40 steps resulting in ∆(2θ ) = 0.05°). The two-dimensional raw data are evaluated to provide di�raction patterns corresponding to di�erent detector heights ranging from 10 mm to 300 mm and variable detector height, accounting for vertical beam divergence e�ects. Thus, asymmetric broadenings at quite low and high scattering angles are overcome, while the full detector height in the medium 2θ regime can be used (Hoelzel et al., 2012). 1 http://jlsrf.org/ http://dx.doi.org/10.17815/jlsrf-1-24 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 1, A5 (2015) http://dx.doi.org/10.17815/jlsrf-1-24 Figure 1: Instrument SPODI (Copyright by W. Schürmann, TUM). Various sample environmental devices enable the characterisation of materials under special condi- tions: A rotatable tensile rig allows in-situ studies under tensile stress, compression stress or torsion while the load axis can be oriented with respect to the scattering plane. A potentiostat for charg- ing/discharging of Lithium ion batteries is available as well as a device to apply high electric �elds on ferroelectrics. 2 Typical Applications • Determination of complex crystal and magnetic structures • Structural evolutions and phase transformations under various environmental conditions • Static and thermal disorder phenomena 3 Research Areas • Ionic conductors • Materials for lithium ion batteries • Ferroelectrics, multiferroics • Hydrogen storage materials • Shape memory alloys • Superalloys • Correlated electron systems • Superconductors • Minerals 4 Sample Environment Standard sample environment of FRM II • Closed cycle cryostat 3 – 550 K (with 3He insert: Tmin = 500 mK) 2 http://dx.doi.org/10.17815/jlsrf-1-24 https://creativecommons.org/licenses/by/4.0/ http://dx.doi.org/10.17815/jlsrf-1-24 Journal of large-scale research facilities, 1, A5 (2015) Figure 2: Schematic drawing of SPODI. • Vacuum high temperature furnace Tmax = 1900°C • Cryomagnet Bmax at SPODI: 5 T • Sample changer (six samples, ambient temperature) Special sample environment • Rotatable tensile rig Fmax = 50 kN, Mmax = 100 Nm • Device for electric �elds Vmax = 35 kV • Potentiostat for electrochemical treatment of materials VMP3 and SP240 5 Technical Data 5.1 Monochromator • Ge(551) wafer stack crystals • standard con�guration: take-o� angle 155° Ge(551): 1.548 Å Ge(331): 2.436 Å Ge(711): 1.111 Å 5.2 Collimation • α 1 ≈ 20’ (neutron guide) • α 2 = 5’,10’, 20’, 25’ nat. (for 155°) α 2 = 10’, 20’, 40’ nat. (for 135°) • α 3 = 10’ 3 http://dx.doi.org/10.17815/jlsrf-1-24 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 1, A5 (2015) http://dx.doi.org/10.17815/jlsrf-1-24 5.3 Detector array • 80 position-sensitive 3He tubes, angular range 2θ = 160°, e�ective height: 300 mm References Hoelzel, M., Senyshyn, A., Juenke, N., Boysen, H., Schmahl, W., & Fuess, H. (2012). High-resolution neutron powder di�ractometer SPODI at research reactor FRM II. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 667, 32 - 37. http://dx.doi.org/10.1016/j.nima.2011.11.070 4 http://dx.doi.org/10.17815/jlsrf-1-24 http://dx.doi.org/10.1016/j.nima.2011.11.070 https://creativecommons.org/licenses/by/4.0/ Introduction Typical Applications Research Areas Sample Environment Technical Data Monochromator Collimation Detector array