MARIA

With scattering under grazing incidence we investigate depth-resolved the laterally-averaged magnetizations and the correlations between their lateral fluctuations. With an additionally polarized neutron beam we derive a vector information on the laterally-averaged magnetization (reflectivity) and on the correlations between their lateral fluctuations (off-specular scattering – µm length scale, GISANS – nm length scale).
In general, MARIA can be used for measurements of magnetic roughness, the formation of magnetic domains in thin layered structures, lateral structures, etc. (polarised mode) and density profiles, structures of solid polymer layers, etc. (unpolarised mode with higher intensity).

Furthermore possible without the need for multilayers investigation of:

• Diluted semiconductors
• Influence of the substrate
• Interfaces between oxide materials

Additionally, the instrument in non-polarised beam mode can be used for reflectometry and GISANS studies of “soft” layers at the solid/ liquid interface by the use of appropriate liquid cells that are available at the beamline. Candidate systems for such investigations include polymer brushes, polyelectrolyte multilayers, biomimetic supported membranes, adsorbed proteins etc. For typical applications involving deuterated solvents the dynamic range that can be expected covers 6 orders of magnitude.

• Hexapod with additional turntable (360°) at sample position, max. load up to 500 kg
• Bruker electromagnet up to 1.3 T
• He closed cycle cryostat down to 4 K

Beside this standard setup the complete sample environment of the JCNS can be adopted to MARIA so that magnetic fields up to 5 T and temperatures from 50 mK to 500 K are available.

Furthermore, MARIA can provide users with a fully equipped Oxid-MBE. The typical sample sizes are 10 × 10 mm² and as targets we can provide Al, Cr, Pr, Fe, La, Nb, Ag, Nd, Tb, Sr, Mn, Ti and Co.

All parts of MARIA are controlled by a computer system according to the “Jülich-Munich” standard based on a Linux workstation. This allows a flexible remote control with automatic scan programs, including the control of sample environment as cryostat and electromagnet.

• Neutron guide NL5-N:
  • vertically focussing elliptic guide
• Monochromator: Velocity selector
• Wavelength:
  • 4.5 Å – 10 Å (polarised)
  • 4.5 Å – 40 Å (unpolarised)
• Resolution:
  • 10 % velocity selector
  • 1 %, 3 % Fermi chopper
• Double reflection polariser
• Horizontal scattering plane

• Expected pol. flux 5 · 10⁶ n cm^-2 s^-1 for 3 mrad collimation

• 4100 mm distance S1 – S2 (collimation)
• 400 mm distance S2 – sample
• 50 mm × 40 mm (w × h) max. opening S2
• 1910 mm distance sample – detector
• 120° maximum detector angle
• GISANS option: 4 m collimation length

• Reflectometry:
  • Q_z- range 0.002 Å^-1 – 3.2 Å^-1
  • Q_x- range 6 · 10^-5 Å^-1 – 0.001 Å^-1
  • α_f -14° – 100°
• GISANS option:
  • Q_y- range 0.002 Å^-1 – 0.2 Å^-1

• ³He cell (off-specular and GISANS)
• Supermirror analyzer (specular reflectivity)

Different type of solid state Li-batteries and battery materials.

• Expected thermal equivalent flux 0.7 · 10⁸ n cm^-2 s^-1 (10 × 20 mm²)
• Nominal limit of quantization for ⁶Li ~ 10¹³ at/cm²
• Energy resolution (alpha-particles) < 11 keV