On the Surface- and Material Science (SMS) branch there are two focal points; the first one is inside the permanent UHV end station and the second one (2.5 m downstream) is on open port, which can be used for user-provided end stations.

The permanent UHV end station on the SMS branch is dedicated to photoelectron and x-ray absorption spectroscopy studies on surfaces and thin films. It comprises four chambers: an analysis chamber with detectors, two preparation chambers with sample transfer and treatment facilities, and a fast entry chamber with a sample garage. Main characteristics of this system are described below.

 

A 3D model of this system is available to the potential users on request.

 

Analysis chamber

Base pressure3⋅10-10mbar
Sample manipulation4-axis LHe/LN2 manipulator (VG Omniax):
3 motorized translations x,y = ±12.5 mm, z = 600 mm and 1 motorized rotation: 360° polar angle
Omicron flag-type sample holders
SourceLPU 54.4 mm
Beam size at sample Defocused (FWHM, h x v): up to 1 x 0.4 mm
Focused (FWHM, h x v): 50 x 0.75*[exit_slit_opening] μm; further reduction in size is possible with baffles (at the cost of flux)
(look here for a picture)
CoolingOpen-cycle He-flow cryostat (a custom-made variant of Janis ST-400)
LN2: ~90 K on sample (most standard mode of cooling)
LHe: ~21 K on sample (Cu-manipulator head, requires venting, rebuilt and baking)
LHe: ~35 K on sample (Mo-manipulator head)
On-sample K-type thermocouple sensor for both heads (transferrable with the sample plate) to ensure exact T measurements
If necessary, a Si-diode sensor may be mounted close to the sample area for more precise low-T measurements (at the cost of reduced heating capabilities)
Magnetic shieldingμ-metal liner
Detectors- DA30-L(W) analyzer since summer 2021
- NEXAFS MCP detector for PEY and TEY experiments
- NEXAFS in TEY mode via sample drain current
- NEXAFS in partial FY mode with Sirius 70 mm2 active area SDD (Rayspec) and Xspress3mini pulse processor (Quantum Detectors)

 

Main preparation chamber (for relatively clean sample preparation procedures)

Base pressure3⋅10-10mbar
Sample manipulation Same main manipulator as for the analysis chamber (VG Omniax); magnetic transfer arms (FerroVac)
Sputter gunYes (Physical electronics)
HeatingTwo types of manipulator heads are available depending on the temperature range of an experiment:
1. Mo-based manipulator head for better heating. Radiative heating by filament (up to 800 C), e-beam heating (up to 1200 °C, but only very shortly) and direct current heating (up to 1400 °C)
2. Cu-based manipulator head for better cooling. Up to 200 °C with a button-heater.
On-sample K-type thermocouple sensor for both heads.

CoolingSame as for the analysis chamber
CharacterizationLEED (OCI Vacuum Microengineering, LPS075-D)
RGA (MKS Microvision 2)
Deposition2 quick install deposition source ports CF 40 (behind a gate valve)
Additional CF40 ports if necessary
Evaporators on request
Quartz thickness monitor on request
DosingGas-sending system with 4 separate gas lines (more on request) and 1 liquid vapor line connected to leak valves on the chamber; gas cabinets and pumping (please discuss gas usage with BL staff in advance)
OtherSample garage for storing up to 6 samples in UHV.
On demand: wobble sticks, vacuum files, vacuum screwdrivers, etc. Possibility to attach vacuum suitcase for transfer samples to/from MAX IV STM (to be requested in advance).

 

Secondary preparation chamber (for molecular film depositions and other less clean preparations)

Base pressure5⋅10-10mbar
Sample manipulation4-axis LN2 manipulator (Prevac, customized):
3 translations: x,y = ±12.5 mm, z = 150 mm
1 rotation: -180°…+150° polar rotation
Only z and rotation are motorized

Magnetic transfer arms (FerroVac)
Sputter gunYes (Thermo VG Scientific)
HeatingMo-based manipulator head, on-sample K-type thermocouple sensor
Radiative heating by filament (up to 800 °C)
Electron beam heating (up to 1200 °C)
Direct current heating (up to 1400 °C)

Coolingno
Deposition4 CF40 ports for user supplied evaporation sources, some gated with valves for quick equipment installation
Thickness monitor on request
DosingTwo gas lines + leak valves (one of them always for Ar)

 

Fast entry chamber

Ultimate base pressureDown to 3⋅10-8mbar
Sample storageCapacity: 6 sample plates
Venting time30 sec
Pumping time20 min to enable transfer (p = 2⋅10-6mbar);
2 hours + LN2 trap to reach ultimate base pressure

 

Analyzer

TypeScienta DA30-L(W)
(a version of DA30-L with extended Ekin range in deflection and angular modes)

Acceptance30° full cone acceptance without sample rotation
(±19° in Transmission mode)
Energy resolution< 1.8 meV FWHM at 2 eV pass energy and 20 eV kinetic energy
Angular resolution< 0.1 degree in both Theta X and Theta Y
Detector40 mm MCP/CCD detection system:
- Energy channels available simultaneously: >1000
- Angular channels available simultaneously: >750
- Total noise counts for all energy channels: < 2 cps
- Average noise per channel: < 0.01 cps
- Available dynamic range per pixel: > 7 bit
- Detector information read-out rate: 400 Mbit/s
SlitsOrientation: horizontal
Shape: straight for all sizes
Width in mm (without aperture): 0.1 , 0.2, 0.3.
Width in mm (with aperture): 0.2, 0.3, 0.5, 0.8, 1.5, 2.5.
ModesTransmission (up to 1500 eV)
Transmission XPS (up to 1500 eV)
Deflector-Angular ±15° for 0.1 and 0.8 mm focus (up to 200 eV)
Angular ±7°,±15° , for 0.1 and 0.8 mm focus each (up to 200 eV)
Pass energiesIn Angular and Deflection modes: 2, 5, 10, 20 and 50 eV
In Transmission mode: 2, 5, 10, 20, 50 100 and 200 eV