LEED 800 | © Scienta Omicron
LEED 800 optics with retraction and shutter.
LEED 800 | © Scienta Omicron
LEED 800 optics with retraction and shutter.
Digital LEED AES Controller Display Model LPS075-D | © Scienta Omicron
Model LPS075-D power supply for LEED operation.
Display of the LPS300 and LOA10-AES systems  | © Scienta Omicron
Model LPS300-D and LOA10-AES power supply for LEED and AES operation.
Example screenshot of the LIM12 software that is compatible with the LEED 800 | © Scienta Omicron
AES Software Images.

LEED 800

Full Flange Size LEED for Higher Angular and Energy Resolution

LEED

  • High energy and image resolution for LEED and AES with no Moire pattern interference
  • Large Angle (100°) Fluorescent LEED Display and superior magnetic shielding
  • Miniature electron gun with large coherence width double focusing
  • Suitable for In Situ Film Growth Monitoring
  • Low outgassing rate
  • Convenient LEED Image Capture with External CCD Camera
  • Simple and Powerful Operation with Digital Controller

The LEED 800 with integral shutter has LEED and AES capabilities using a miniature electron gun, set of concentric grids and a conductive, phosphor coated screen. It is an extremely reliable high-performance LEED instrument which operates with up to date digital power supply. The retraction mechanism has outstanding mechanical properties ensuring smooth day-to-day operation as experienced by our large user base over decades. The LEED 800 delivers exceptionally sharp and bright LEED patterns with high resolution in k-space (typical transfer width of 300 Å at 100 eV). The wide viewing angle (100° at 75 mm sample distance) and minimal shadowing of the screen by the miniature electron gun give a maximum visible LEED pattern.

More Information

Applications

Display of the LEED pattern of a Silicon (111) sample with 120 eV beam energy | © Scienta Omicron
LEED pattern of a Silicon (111) sample with 120 eV beam energy.

The LEED 800 is capable of providing LEED and AES data for a wide range of samples.  The larger size allows for higher angular and energy resolution.

Display of the LEED pattern of Strontium Titanate (100) with 95 eV beam energy. | © Scienta Omicron
LEED pattern of Strontium Titanate (100) with 95 eV beam energy.
LEED pattern of Silicon Carbide 6H (0001) with Titanium with 130 eV beam energy. | © Scienta Omicron
LEED pattern of Silicon Carbide 6H (0001) with Titanium (estimated deposited layer thickness of 56.0 mm) with 130 eV beam energy.
LEED pattern of Yttrium Iron Garnet with 15 eV beam energy | © Scienta Omicron
LEED pattern of Yttrium Iron Garnet with 15 eV beam energy.

Drawings

Technical drawing of Scienta Omicron's LEED 800 product with back, front and side views  | © Scienta Omicron
Side view of LEED 800 (model BDL800IR) optic.

For seamless integration, 3D step files are available for all models. 

Technical drawing of the LEED 800 Front View  | © Scienta Omicron
Front view of the LEED 800 (model BDL800IR) optic.

LMX length calculation for LEED 800 (model BDL800IR):

FS = 155 mm + 2LMX – OV + WD; where FS is the flange to sample distance, LMX is the retraction distance, OV is the overlapping distance, WD is the working distance and the 155 mm value is a constant related to this optic model.

If the calculated FS value is longer than the actual port length a nipple adapter can be added as a spacer between the LEED optics and the UHV chamber. The nipple length can be calculated as follows:

NL = FS – PL; where NL is nipple length and PL is port length. 

Technical drawing of the LEED 800 Back View  | © Scienta Omicron
Rear view of the LEED 800 (model BDL800IR) optic.
Technical drawing of the LEED 800 side view  | © Scienta Omicron
Side view of the LEED 800 (model BDL800IR) optic.

Configuration Guide and Specifications

The LEED 800 optics is controlled using either a LPS075-D or LPS300-D power supply. The LPS075-D is used to operate the optic in LEED mode only whereas the LPS300-D in conjunction with the LOA10-AES lock-in controller and AUS30 input coupler is used to operate the optics in LEED and AES modes. Integral shutter (model ISH-8) and LaB6 filament (model LaB6) are further options.

Specifications

Glass-display

Fused silica coated with indium-tin oxide conductive layer and P31 phosphor (ZnS:Ag:Cu-green, 525 nm wavelength)

Acceptance angle

100° angle of acceptance from sample at a distance of 75 mm

Retarding Field Analyser

Concentric assembly of hemispherical grids

Working distance

18 mm from sample

Grid material

Gold coated tungsten wire mesh (100 mesh, 81 % transparency)

Energy Resolution

0.2 % - 0.5 % at low modulation voltages

Monitoring

8" standard viewport

Linear motion

Up to 150 mm retraction from sample (100 mm standard); linear ball bearing and acme thread with all spring electr. connections

Integral Shutter

Manual shutter driven by a rotary feedthrough

Magnetic shielding

Mu-metal cylinder with front cover for maximum attenuation

Assembly

Extreme-high-vacuum compatibility with stainless steel, high alumina and Au-plated copper alloy materials

Mounting

8"(CF150) double sided conflat flange with sample distance 145 mm – 500 mm

Bakeability

Under vacuum, 250 °C maximum

Integral Miniature Electron Gun

Beam energy system

LEED – 2 µA at 100 eV and 0.5 mm beam size, AES - up to 100 µA at 3 keV

Beam size

From 1 mm to 250 µm - adjusted by Wehnelt potential, limited by exchangeable aperture down to 50 µm

Electron source

Tungsten-2 % thoriated filament standard, 
single crystal LaB6 filament optional

Energy spread

0.45 eV (thoriated - tungsten filament)

Overall size

10 mm lens diameter and 80 mm length

For full specifications and more information about product options, please do not hesitate to contact your local sales representative.