High-resolution RIXS of solids in the XUV regime at UE112-PGM-1
The meV-RIXS station is dedicated to the element-selective investigation of solid systems by high-resolution RIXS of low energy excitations. Incident photon energies go up to the C K edge (280 eV) giving access to e.g. transition metal M-edges, rare earth N-edges and K-edges of light elements. The station includes an additional complementary lower-resolution / higher-energy range RIXS spectrometer for overview spectra suited for preliminary investigations.Selected Applications:
- dd and spin-flip excitations in transition metal oxides, e.g. NiO or La2CuO4 at the transition metal M2,3 edges
- f-electron multiplet excitations in rare-earth compounds at the RE N45 edges. Chemical shifts with core-to-core RIXS.
- Lattice vibrations and electron phonon coupling in the light elements Be to B using the K edge.
|Energy range||8 - 690 eV; for extreme values (<50 eV or >400 eV) contact the beamline crew|
|Energy resolution||30,000 (20-150eV)|
> 20,000 (150-350eV) (standard grating)
|Flux||> 2x1012 ph/s (20-280eV)|
ca. 4x1013 ph/s (50-150eV) (standard grating)
|Focus size (hor. x vert.)||optimum: ca. 0.001 x 0.02 mm (V x H, FWHM, inside sample chamber)|
|Phone||+49 30 8062 14836|
|Temperature range||Base temperature of liquid N2 and He, full temperature control in testing|
|Pressure range||UHV range (<10-9 mbar)|
|Detector||Microchannel plate + delay line detector|
|Sample holder compatibility||Custom-made sample holder for solid samples of dimensions 10x10x5 mm or smaller|
The meV RIXS plane grating spectrometer consists of two parabolical mirrors with a plane grating in between. The first mirror collects and collimates the scattered radiation onto the grating while the second mirror focusses the diffracted light onto the detector. The spectrometer houses two laminar grating structures on a common substrate: 1050 l/mm for high transmission and 4200 l/mm for high resolution. The photons are detected by a PHOTONIS multi channel pate (MCP) stack in combination with a RoentDek delay line detector DLD-120. The MCP channel diameter is 25 um and the top MCP is coated with CsI to improve the quantum efficiency of the detector.
The samples are mounted directly to a Janis ST-500 Microscopy Cryostage which allows for a maximum stability for the sample position. To avoid mechanical instabilities in sample positioning, no sample translation stage is installed, but the whole vacuum chamber can be positioned by a 3-axis Huber table vertically and in the horizontally. Rotation of the sample around the vertical axis is achieved via a rotation of the microscope cryostage.
For details and current status of the experimental station contact the station scientist.