Specifications


Specifications

General Properties
Beamline Energy Resolution14 [meV] @ 100 [eV]
100 [meV] @ 400 [eV]
Beamline Resolving Power7.5 * 103 [deltaE/E] @ 100 [eV]
4 * 103 [deltaE/E] @ 400 [eV]
Beamline Energy Range25 - 1000 [eV]
Max Flux On Sample1.5 * 1013 [ph/s] @ 150 [eV]
6.5 * 1011 [ph/s] @ 400 [eV]
Spot Size On Sample Hor20 - 30 [um]
Spot Size On Sample Vert3 - 10 [um]
Angle Of Incidence Light On Sample Value16 [degrees]
Control And Data Analysis
Control Software Typecustom developed code written in Java; data acquisition is carried out by means Python (Jython) scripts
Data Output Typeimages, spectra
Data Output Formattiff 16 bit, ASCII files
Softwares For Data Analysisimage suite based on Wavemetrics Igor Pro (Version 6 or later)



Photon Sources

2 Sasaki type elliptical undulators phased by an electromagnet

TypeUndulator
Available PolarizationElliptical
Variable PolarizationYes
Source Size SigmaX = 39.2 [um], Y = 3 [um]
Source Spectral Flux2.1 * 1018 [ph/s/0.1%bw] @ 400 [eV]
Energy Range10 - 1000 [eV]
Number Of Periods20
Period10 [cm]

[the optimum phase for measurements requiring circular polarisation can be found here]


Additional Lightsources

Hg lamp

TypeLamp
Central Wavelength/Energy365 [nm]
Beam shapeGaussian
PolarisationLinear Horizontal



Monochromators

SG10 Spherical grating

Energy Range10 - 50 [eV]
TypeSGM
Resolving Power1000 [E/deltaE] @ 20 [eV]
Number Of Gratings1
Grating TypeSpherical Grating

VLS 200 grating

Energy Range50 - 300 [eV]
TypeVariable Line Spacing grating
Resolving Power4000 [E/deltaE] @ 200 [eV]
Number Of Gratings1
Grating Type200 lines/mm

VLS 400 grating

Energy Range100 - 1000 [eV]
TypeVariable Line Spacing Grating
Resolving Power4000 [E/deltaE] @ 400 [eV]
Number Of Gratings1
Grating Type400 lines/mm

Resolving power data at 200mA ring current, 2.0 GeV; 10 μm exit slit width. The monochromator has been recently upgraded to solve long term stability issues and improve mechanical and optical operation. Our tests demonstrate that the instrument is now extremely stable. A report on the instrument performance is available here.


Endstations

SPELEEM III (Spectroscopic photoemission and low energy electron microscope)

MicroscopesSpectroscopic photoemission and low energy electron microscope (SPELEEM III, Elmitec GmbH), with magnetic triode objective and 120° separator.
Imaging techniques: LEEM, EELS-LEEM, XAS-PEEM, XMCD-PEEM, XMCLD-PEEM;
microspot diffraction techniques: μ-LEED, μ-ARUPS, μ-ARPES, μ-EELS, μ-XPD.
microspot spectroscopy techniques: μ-ARUPS, μ-ARPES, μ-XPD, μ-LEED, μ-EELS.
Contrast apertures : 10, 30 and 100 µm.
Illumination apertures (size on sample): 500 nm, 1 and 6 µm.
Lateral resolution: 10 nm in LEEM, 30 nm in XPEEM
Sample types: UHV compatible, flat with resistivity of few tens Ohms / cm
SpectrometerHemispherical energy analyzer Elmitec R200
pass energy: 820 eV
energy resolution:
100 meV (spectral imaging)
100 meV (diffraction imaging)
60 meV (microspot spectroscopy)
Base Pressure7 * 10-11 [mbar]
Detectors AvailableRetiga R6 CCD
flange mounted Chevron MCP
Endstation OperativeYes
Sample
Sample TypeCrystal, Amorphous
Other Sample Typemicro-structured, lithographically patterned samples
Mounting TypeElmitec sample cartridge, custom designed sample cartridge
Required Sample SizeX = 9 [um], Y = 9 [um], Z = 1 [um]
Manipulator or Sample stage
Elmitec Manipulator with motorized x,y stage, tilt and azimuthal rotation
Descriptionmotorized sample tilt with minimum step size of 0.01°
Degrees Of Freedom6
Translator Stages2
Cradles1
Positioning PrecisionX = 66 [nm], Y = 66 [nm]

Sample Environment
Sample Cartridge for Elmitec LEEM III Environment
Pressure (min)7 * 10-11 [mbar]
Pressure (Max)5 * 10-5 [mbar]
Temperature100 - 2000 [K]

Sample Holders
Sample cartridge for in-situ, in-plane magnetization
TypeCustom made sample cartridge
Descriptionthe cartridge allows applying magnetic fields up to 300 Gauss in-plane, normal to the beam propagation direction.
Sample heating is not possible.

Sample cartridge for in-situ, out-of-plane magnetization
Typecustom made sample cartridge
Descriptionthe cartridge allows applying magnetic fields up to 30 Gauss in the out-of-plane direction. Sample heating is not possible.

Standard sample cartridge for Elmitec LEEM III microscope
TypeElmitec LEEM III
DescriptionThis sample cartridge allows radiative and e-beam heating. It can perform prolonged sample annealing up to 1200 °C and short flashes up to 1600°C. The sample temperature is measured using a type C thermocouple.

Magnetic Fields
Magnetization stage in UHV
DC FieldsDC fields can be applied in the in-plane or out-of-plane directions in the main chamber of the SPELEEM microscope (but not in measurement position!).
Max DC Field2 * 103 [Gauss]




The sample temperature is read by a type C thermocouple (W5%Re/W26%Re), which is mounted close to the sample, or with an optical pyrometer. The type C thermocouple calibration parameters can be found here.

Important note on samples

It is very important is to keep in mind that not all samples are suitable for XPEEM experiments and special requirements have to be fulfilled. Samples must be conductive and resistant to radiation damage. It is essential that they are free from field emitters and tips. The sample geometry must also satisfy basic requirements. Lithographically patterned samples have to be carefully designed.



Detectors

flange mounted Chevron MCP

TypeAdvanced Performance Long-Life™ Microchannel Plate Detector with fiber optics viewport: APD 2 40/12/10/8 I 60:1 6"FM P20
Detection
Detected ParticleElectron

Retiga R6 CCD

Typesensor type: Sony ICX-695 Scientific Interline CCD
DescriptionQuantum efficiency 75% at 600nm
Pixel SizeX = 4.54 [um], Y = 4.54 [um]
Array SizeX = 2688 [pixel], Y = 2200 [pixel]
Dynamic Range1.6384 * 104 [bit]
Signal/NoiseRatio5.5 [e-]
Output Readout SoftwareElmitec UView2002 version 19.9.0
Detection
Detected ParticleElectron


Experimental Facilities

  • Gas line with two precision leak valves (Varian).
  • e-beam evaporators (3 Omicron and 1 Elmitec).
  • One retractable stage for mounting e-beam evaporators without breaking vacuum.
  • Magnetisation stage (current - magnetic field calibration table)
  • Detector gating for time resolved XMCD, LEEM and LEED experiments
  • Preparation chamber with Ar sputtering, gas line and sample heater.
  • sample storage in main chamber (up to 3 cartridges).
  • SRS 100 and MKS quadrupole mass spectromenters.

References

  1. Cathode lens spectromicroscopy: methodology and applications;
    T. O. Menteş, G. Zamborlini, A. Sala, A. Locatelli;
    Beilstein J. Nanotechnol. 5, 1873–1886 (2014) [Published 27 Oct 2014];
    doi: 10.3762/bjnano.5.198;
  2. Photoemission electron microscopy with chemical sensitivity: SPELEEM methods and applications;
    A. Locatelli, L. Aballe, T.O. Menteş, M. Kiskinova, E. Bauer;
    Surf. Interface Anal. 38, 1554-1557 (2006).
    doi: 10.1002/sia.2424
Ultima modifica il Giovedì, 05 Maggio 2022 14:38