Elastic Diffuse Scattering Spectrometer
CORELLI | BL-9 | SNS
CORELLI Features
- CORELLI’s unique correlation chopper, or cross-correlation technique, is the key optical component allowing for energy discrimination.
- CORELLI’s white beam Laue Diffraction allows for efficient data acquisition.
- CORELLI’s large detector bank allows large coverage in reciprocal space.
- CORELLI is capable of implementing versatile sample environments at SNS including low-temperature, high magnetic field.
- CORELLI Commissioning
Single Crystal Diffraction with Elastic Discrimination
A cross-correlation method is used to reconstruct the (quasi)elastic signal from the CORELLI data. Data were collected on a SrTiO3 single crystal (25 mm3) at 300 K with the correlation chopper (2 days). (left) The phonon excitation (6.8 meV) is clearly observed in the total diffraction data, e.g. lines along (H, 5.4, 2.5) and (H, 5.6, 2.5)). (right) The phonon excitation (inelastic scattering) contribution has been largely removed after the cross correlation analysis.
Short-Range Chemical Order
Elastic diffuse scattering from an Fe72Pt28 Invar single crystal. The butterfly shape scattering near the Bragg peaks is from short-range correlations (2 days). Data were collected at 10 K with a closed cycle refrigerator (Tbase = 6 K).
Short-Range Magnetic Order
(Left) Frustrated pyrochlore Dy2Ti2O7 has the local “two-in and two-out” spin configuration at the ground state simulating the ice rule in water ice. (Right) Magnetic scattering at 300 mK of Dy2Ti2O7 in the (H,H,L) scattering plane, which comes from the short-range correlation of the Dy magnetic moments (6 days). Reference data collected at 20 K were deducted. The single-crystal sample was cooled inside a 3He insert (Tbase = 300 mK) and a cadmium mask was used to reduce scattering from sample environment.
High Pressure Neutron Diffraction
(a-c) Diffraction patterns from a MnP single crystal (5 mm3) at 230 K, 270 K and 6 K, respectively. (d-e) The temperature dependence of the order parameter of the incommensurate AFM and FM orders at 1.8 Gpa (5 days). (f) The CuBe pressure cell (Pmax = 1.8 GPa) used during the neutron experiments. Details see: Matsuda et al. PRB 93, 100405(R) (2016)
Magnetic Diffraction from Epitaxial Thin Films
Temperature dependence of the magnetic diffraction from a [1 u.c. LaMnO3/1 u.c. SrMnO3]40 superlattice (totally 30 nm * 180 mm2) at 300 K (left) and 4 K (right). A-type AFM with a modulation wavevector (0, 0, ½) has been observed below TN ( 2 days).
Magnetic Diffraction from Small Crystals
Magnetic diffraction of spin-orbit coupled honeycomb lattice iridate Na2IrO3 (mass of 10 mg). In contrast to the theoretically proposed stripy order, a zigzag magnetic order was observed with a small moment of 0.2 µB/Ir.
Neutron scattering in High Magnetic Fields
(left) Schematic of an in-house designed and fabricated pulsed magnetic field gadget, up to 35 T with a pulse width ~ 3 ms and a repetition rate of ~ 5 minutes per pulse (Dr. Garrett E. Granroth, ORNL). (right) Temperature dependence of the diffraction pattern from a Co3TeO6 single crystal mounted inside a pulsed field gadget without magnetic field applied.
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