European Synchrotron Radiation Facility
BM25 - GIXRD, SRD, XRR, SC and HAXPES endstation

The Spanish CRG BM25B - SpLine beamline is dedicated to structural investigations using hard X-ray scattering mostly in materials science, specialized on X-Ray diffraction techniques and hard X-ray photoemission spectroscopy.

BM25B is located on the hard edge of the bending magnet D25 with a critical energy of 20.6 keV. The optics accepts 2 mrad of the horizontal radiation fan and produces a small focal spot at different positions (B1 and B2) in the experimental hutch B. The beamline is intended for Single Crystal Diffraction (SCD), Grazing incidence X-ray diffraction (GIXRD), Surface and Interface X-Ray Diffraction (SXRD), X-ray reflectivity (XRR) and Hard X-Ray Photoelectron Spectroscopy (HAXPES). At SpLine, we have developed a novel set-up that combines HAXPES and x-ray diffraction (surface/interface and bulk x-ray diffraction, and x-ray reflectivity). Both techniques can be operated simultaneously on the same sample using the same excitation source.

Grazing incidence and single crystal X-Ray diffraction station

The main objective of this end-station is to provide a large variety of X-ray diffraction experiments for the Spanish scientific community, as well as for foreign scientists around the world. An important aspect, which has been one of the major goals of the end-station during the design, start-up and upgrade periods, is the adaptability and flexibility for different sample environment set-ups that must be easily installed to allow for a high throughput of users. It is conceived to carry out X-Ray Reflectivity (XRR), Surface X-Ray Diffraction (SXRD), Single Crystal Diffraction (SCD), Reciprocal Space Maps (RSM), Grazing Incidence X-Ray Diffraction (GI-XRD) and High Resolution Powder Diffraction (HRPD) experiments. Thus, the multipurpose character of the end-station is reflected on the huge variety of experiments carried out in the last years, showing multidisciplinary work areas, from surfaces and thin films to liquid crystal materials.

The multipurpose X-ray diffraction set-up is mainly composed of a six-circle diffractometer in vertical geometry equipped with a 2D MaxiPix detector placed on the diffractometer arm and a CCD detector mounted on an independently motorized stage. The sphere of confusion for the whole collection of circles is 50 μm. There are many experiments that can be carried out on this multipurpose diffractometer. Among them, the study of surface and buried interfaces morphology on thin and ultra-thin films are predominant. The possibility to perform high resolution reciprocal space maps (RSM) in combination, under the same set-up, with low- and high-angle XRR and with Surface and Interface X-ray Diffraction enables a unique method for a complete structural and morphological characterization of thin films and multilayers.

Surface X-Ray Diffraction, Grazing incidence X-ray diffraction, X-ray reflectivity and Hard X-Ray Photoelectron Spectroscopy Station

The second focal point on Branch B hosts a state-of-the-art set-up dedicated to the simultaneous combination of X-ray Diffraction and Hard/Soft X-ray Photoelectron Spectroscopy. Such a set-up offers the unique possibility to correlate the atomic structure of the sample with its compositional, chemical and electronic properties. This is of particular importance for many systems, such as complex oxides or topological insulators, i.e., strongly correlated electron systems, for which their macroscopic properties are intimately related to an intricate interplay between charge, spin, and lattice degrees of freedom. Also the combination of X-ray reflectivity with hard and soft X-ray photoelectron spectroscopy is crucial for retrieving an accurate non-destructive compositional and electronic depth profile in the tens of nanometres depth-scale with nanometre resolution in amorphous, polycrystalline, single crystalline samples or hetero-structures. Furthermore, the ability to tune the excitation energy in the hard X-ray regime enables tuning the sampling depth, i.e. depth profile analysis, but also enables the discrimination between bulk and surface effects, especially if combined with variable incident angle and with soft x-ray excitation. Such a combination of techniques finds its optimal use in-situ experiments, .i.e., in-situ growth or in-situ treatment, as it is the only possibility to guaranty an accurate correlation between structural, compositional, chemical and electronic properties.

Beamline Energy Resolution
1.4 * 10-4 [eV] @ 10000 [eV]
Beamline Energy Range
7000 - 23000 [eV]
Max Flux On Sample
3 * 1011 [ph/s] @ 17000 [eV]
Spot Size On Sample Hor
300 - 5000 [um]
Spot Size On Sample Vert
300 - 2000 [um]
Angle Of Incidence Light On Sample Value
0 - 45 [degrees]
Photon Sources

BM25

Type
Bending Magnet
Available Polarization
Linear horizontal
Source Divergence Sigma
X = 99 [urad], Y = 0.36 [urad]
Source Size Sigma
X = 113 [um], Y = 11 [um]
Source Spectral Brightness
4 * 1015 [ph/s/mrad^2/mm^2] @ 12.4 [eV]
Source Spectral Flux
2 * 1012 [ph/s/0.1%bw] @ 12.4 [eV]
Monochromators

DCM Double-Crystal Monochromator

Energy Range
5000 - 45000 [eV]
Type
The monochromator is a pseudo channel-cut with two fixed Si (111) crystals moved together by a simple goniometer circle, in the (-n, +n) configuration. The horizontal focusing is achieved by the second monochromator crystal through a sagittal cylindrical bending. The first monochromator crystal is ethanol-cooled while the second crystal is kept at room temperature. The second crystal is equipped with a long-travel piezoelectric actuator (Nexline-inchworm PI) that allows us to change very slightly the Bragg angle (pitch adjustment). Two additional long-travel piezo actuators are used for the movements roll and yaw of the second crystal.
Resolving Power
1.4 [deltaE/E] @ 12400 [eV]
Endstations or Setup

Hard X-ray Photoelectron Spectroscopy X-ray Surface Diffraction

Diffractometer
The experimental set-up includes a heavy 2S+3D diffractometer, a UHV chamber and an electrostatic analyzer. The vacuum chamber has two Be windows so that the incoming and outgoing X-ray beam can hit the sample and the X-ray detector, respectively. The exit Be-window allows the out-going diffracted X-ray beam to cover 120º in-plane and 50º out-of-plane. The in-coming Be-window is wide enough to reach up to 50º X-ray incidence angle. A wide portion of the reciprocal space (Qmax=10 Å-1 at 12 keV) is therefore accessible. The UHV chamber has also MBE evaporation sources, an ion gun, an electron gun (up to 15 keV), an X-ray tube (Mg and Ti anodes), a UV discharge lamp, a LEED optics, a sample heating (up to 1800 K) and a cooling device (down to 20 K on the sample), leak valves, mass spectrometer and a load-lock for in-vacuum sample transfer.
Spectrometer
The analyzer is an electrostatic cylinder-sector (FOCUS HV CSA), with a compact geometry and high transmission due to second order focusing. The analyzer is based on a cylinder sector with 90° deflection and 300 mm slit-to-slit distance. The sample-lens distance is maximized to 50 mm, allowing the simultaneous accomplishment of photoemission and diffraction experiments. This gives a very compact design of the analyzer that is easily integrated into a multipurpose experiment with different techniques. The analyser is capable of handling kinetic energies both up to 15 keV and down to a few eV with the same analyser setup and power supply. The electron analyzer is mounted on a 3-linear motion (x, y, z) motorized table so that the analyser focal point position can be swept on the sample. In this way, the detection geometry and consequently the counting rate can be optimized without changing the sample position or the in-coming beam impact point, i.e., without disturbing the diffraction geometry conditions. A 2x2 MAXIPIX (512x512 pixels) detector is installed on the diffractometer detector arm reducing considerably the acquisition time for the diffraction pattern.
Base Pressure
1 * 10-10 [mbar]
Endstation Operative
Yes

Sample

Sample Type
Crystal
Other Sample Type
Thin films
Mounting Type
clamps
Required Sample Size
X = 10000 [um], Y = 10000 [um], Z = 1000 [um]

Techniques usage

Diffraction / Surface diffraction
The experimental set-up includes a heavy 2S+3D diffractometer, a UHV chamber and an electrostatic analyzer. The vacuum chamber has two Be windows so that the incoming and outgoing X-ray beam can hit the sample and the X-ray detector, respectively. The exit Be-window allows the out-going diffracted X-ray beam to cover 120º in-plane and 50º out-of-plane. The in-coming Be-window is wide enough to reach up to 50º X-ray incidence angle. A wide portion of the reciprocal space (Qmax=10 Å-1 at 12 keV) is therefore accessible. The sample surface is mounted vertically. The X-ray beam enters and exits the vacuum system through Be-windows, welded into the stainless-steel chamber, which are strong enough to support UHV conditions. An ion bombardment gun, evaporation and gas leakage sources are also mounted on the UHV chamber that allows to perform X-ray diffraction and HAXPES experiments during growth deposition. It is conceived to carry out X-Ray Reflectivity (XRR), Surface X-Ray Diffraction (SXRD), Reciprocal Space Maps (RSM), Grazing Incidence X-Ray Diffraction (GI-XRD) and Grazing Incidence High Resolution Powder Diffraction (GI-HRPD) experiments under UHV conditions.
Photoelectron emission / XPS
HAXPES - Hard X-Ray Photoelectron Spectroscopy measurements can be performed within a photon energy range between 7 and 23 keV and an electron kinetic energy range between a few eV and 15 keV.The analyzer is an electrostatic cylinder-sector (FOCUS HV CSA), with a compact geometry and high transmission due to second order focusing. The analyzer is based on a cylinder sector with 90° deflection and 300 mm slit-to-slit distance. The sample-lens distance is maximized to 50 mm, allowing the simultaneous accomplishment of photoemission and diffraction experiments. The sample moves on the diffractometer coupled into the vacuum by a rotating feedthrough, which is composed of a differentially pumped rotating seal and a bellow that enables the adjustment of the vessel with respect to the diffractometer. A specially designed mini-LEED mounted on a 63 mm flange is incorporated on the UHV system so that pre-characterisation of the ordered surface can be done. An ion bombardment gun, evaporation and gas leakage sources are also mounted on the UHV chamber that allows to perform X-ray diffraction and HAXPES experiments during growth deposition.

Manipulator or Sample stage

Degrees Of Freedom
5
Translator Stages
1
Cradles
4

Sample Environment

Pressure (min)
1 * 10-10 [mbar]
Pressure (Max)
1 * 10-5 [mbar]
Temperature
30 - 1200 [K]

Multipurpouse X-ray Diffraction

Diffractometer
A six-circle diffractometer in z-axis geometry enables different sample environments. It is conceived to carry out X-ray reflectivity, surface X-ray diffraction, single crystal diffraction, reciprocal space maps, grazing incidence X-ray diffraction and high resolution powder diffraction experiments. It is conceived to carry out X-Ray Reflectivity (XRR), Surface X-Ray Diffraction (SXRD), Single Crystal Diffraction (SCD), Reciprocal Space Maps (RSM), Grazing Incidence X-Ray Diffraction (GI-XRD) and High Resolution Powder Diffraction (HRPD) experiments.
Detectors Available
2x2 MaxiPix
VHR 3x1 X-ray Camera
Endstation Operative
Yes

Manipulator or Sample stage

Degrees Of Freedom
7
Translator Stages
3
Cradles
4
Positioning Precision
X = 500 [nm], Y = 500 [nm], Z = 200 [nm]
Range Of Movement
X = 30000 [um], Y = 30000 [um], Z = 4000 [um]

Sample Environment

Pressure (min)
1 * 10-10 [mbar]
Pressure (Max)
5 * 103 [mbar]
Temperature
40 - 1000 [K]
Detectors

2x2 MaxiPix

Type
Hybrid Photon Counting pixel detector
Description
MAXIPIX is a fast readout, photon-counting pixel detector system developed by ESRF and based on the Medipix2 and Timepix readout chips developed by CERN and the Medipix2 collaboration.
Pixel Size
X = 55 [um], Y = 55 [um]
Array Size
X = 512 [pixel], Y = 512 [pixel]
Thickness
50 * 101 [um]
Passive or Active (Electronics)
Active
Output Readout Software
ESRF "LIMA" library
ESRF MAXIPIX device server
ESRF "Oxidis" image viewer
TANGO
SPEC runtime with ESRF macros (user interface)

Detection

Detected Particle
Photon

FOCUS HV-CSA electron energy analyzer

Type
The concept of the analyzer is based on the well proven Cylindrical Sector Analyzer (CSA). Compared to a conventional hemi-spherical analyzer, the CSA allows collection of a larger solid angle of electrons at the same energy
resolution, which is of great importance to ensure excellent count rates and sensitivity at high kinetic energies. The FOCUS HV-CSA is a Cylindrical Sector Analyzer (CSA) with a slit to slit distance of 300mm.
It is designed to achieve optimum performance in a wide kinetic energy range between 1eV and 15keV.
Description
The analyzer is based on a cylinder sector with 90° deflection and 300 mm slit-to-slit distance. The sample-lens distance is maximized to 50 mm, allowing the simultaneous accomplishment of photoemission and diffraction experiments. This gives a very compact design of the analyser that is easily integrated into a multipurpose experiment with different techniques. The analyzer is capable of handling kinetic energies both up to 15 keV and down to a few eV with the same analyzer setup and power supply. The electron analyzer is mounted on a 3-linear motion (x, y, z) motorized table so that the analyzer focal point position can be swept on the sample.
Passive or Active (Electronics)
Active

Detection

Detected Particle
Electron

VHR 3x1 X-ray Camera

Type
X-ray CCD array detector
Description
Three very high-resolution 31.2 microns pixel size X-ray digital camera modules with direct coupled (micro) fibre-optic input and water cooled CCD. Camera Quantum Efficiency of 45% @ 550nm at the scintillator emission wavelength, interline transfer cooled CCD sensor with typical ∆T of > 50OC allowing shutter less simultaneous exposure and read out cycles
Pixel Size
X = 32.8 [um], Y = 32.8 [um]
Array Size
X = 7651 [pixel], Y = 3825 [pixel]
Passive or Active (Electronics)
Active
Dynamic Range
12 [bit]
Output Readout Software
ESRF "LIMA" library
ESRF VHRx3 device server
ESRF "Oxidis" image viewer
TANGO
SPEC runtime with ESRF macros (user interface)

Detection

Detected Particle
Electron
contacts
German R. CASTRO
Juan RUBIO ZUAZO
Techniques
Diffraction
  • Crystallography
  • Powder diffraction
  • Surface diffraction
Emission or Reflection
  • Reflectrometry
Photoelectron emission
  • XPS
Scattering
  • Elastic scattering
  • Wide angle scattering
Address
SpLine Spanish CRG BM25 Beamline at the ESRF - The European Synchrotron
ICMM - Instituto de Ciencias de Materiales de Madrid
CSIC - Consejo Superior de Investigaciones Científicas

71 avenue des Martyrs
38000 Grenoble, France
control/Data analysis
Control Software Type
  • SPEC
Data Output Type
  • Spectra, images (EDF),
Data Output Format
  • scii, edf
Softwares For Data Analysis
  • PyMCA, ROD, UniFIT
in partnership with