First Deflector Analyser Preserving Measurement Geometry
- 30° full cone acceptance without sample rotation
- Spin-resolved MDC without sample rotation
- Matrix element effects are avoided by keeping sample fixed
- Ensures same spot for all k//
- Improved ky accuracy (resolution better than 0.1°)
- Patented (WO2013/133739)
- Fast electronic deflection
Besides XPS and UPS, the DA30-L is especially developed for high quality ARPES measurements. Scienta Omicron´s deflector concept enables full cone angular scans in reciprocal space without sample movement. This allows electronic band structure mapping, even spin resolved, of the full surface Brillouin zone without changing measurement geometry, eliminating matrix element effects, and simplifying the interpretation of results dramatically.
With the DA30-L, we presented the world’s first hemispherical analyser using a ground-breaking deflector concept that enables angular scans in two dimensions of k-space without tilting the sample. Since the launch in 2013, the DA30-L has been rapidly accepted by the ARPES community.
Traditional ARPES analysers have an angular mode which is restricted to the angular dispersive θx direction. The detector records a 2D image of intensity for angle θx vs energy E. In such a setup, obtaining full cone measurements requires the sample to be physically rotated to probe the θy angular space. This physical movement can introduce multiple artefacts into the ARPES measurement.
Our analysers overcome these limits by using an internal deflection mode for the θy direction. With this deflection mode, the lens system projects individual slices of θx on to the analyser slit for a given θy angle. Hence, the detector of hemispherical analyser measures slices of θx vs E spectra. Recording these individual slices while changing the θy deflector angle builds a cube of reliable data containing intensity for all θx, θy, and E values.
The deflection mode enables the DA30-L to obtain these full cone measurements with an opening angle of up to ± 15° while avoiding sample rotation, making it an ideal high performance ARPES analyser.
The deflection feature is a big advantage as it allows to keep the sample in a fixed position and instead uses the deflectors to change the angular range in θy projected on to the analyser slit. This ensures the same position of the sample is probed during the whole measurement. In addition, keeping the experimental geometry fixed throughout the measurement sequence avoids matrix element effects which are caused by variations in ionisation cross section for different photon to sample angles. This allows to acquire higher quality data using the faster and more precise electronic deflection compared with mechanical sample movement. Another advantage, for some samples, is that decreased rotation requirements allow manipulators with fewer degrees of freedom to be used. This ultimately allows for lower sample temperatures to be reached.
The EXT analyser model features an extended energy range to lower kinetic energies. While a regular DA30-L is specified from 3 eV kinetic energy for angular/deflection mode, the EXT type analyser is capable of handling kinetic energies starting from as low as 0.5 eV. Achieving good performance at such low energies puts high demands on the analyser lens mechanics. Other specifications remain the same as for the DA30-L.
The DA30-L(W) includes the wide angular and deflection modes for kinetic energy ranges of lab based UV sources. It is mechanically prepared for the full deflection capabilities of the DA30-L mode, but is delivered without the electronics and software necessary for the high dispersive angular and deflection modes. The electronics and software upgrade is offered separately. The final upgrade to DA30-L can be done at customer site without removing the analyser from the system and without breaking vacuum. The upgrade concerns the computer, software, and high voltage system. Hence, this option presents an easy path to gain future access to the full DA30-L deflector concept and kinetic energy range.
The DA30-L(W) supports ±7°/±15° in angular mode and ±15° in deflection mode. The upper kinetic energy range in angular as well as deflection mode is limited to 50 eV.
High Energy Deflection
For experiments that require a higher kinetic energy range in deflection mode an upgrade is available. This upgrade includes electronics and software and extends the kinetic range of the deflection mode up to 800 eV.
< 1.8 meV FWHM
0.5 eV – 1 500 eV
± 3.5°, ± 7°, ± 15°
3 eV – 1 500 eV
For full specifications and more information about product options, please do not hesitate to contact your local sales representative.
3 eV – 200 eV
< 10-5 mbar
NW 200 CF
New Developments in Laser-Based Photoemission Spectroscopy and its Scientific Applications
The significant progress in angle-resolved photoemission spectroscopy (ARPES) in last three decades has elevated it from a traditional band mapping tool to a precise probe of many-body interactions and dynamics of quasiparticles in...
Very Efficient Spin Polarization Analysis (VESPA)
Complete photoemission experiments, enabling measurement of the full quantum set of the photoelectron final state, are in high demand for studying materials and nanostructures whose properties are determined by strong electron and...
Electronic Evidence of Temperature-Induced Lifshitz Transition and Topological Nature in ZrTe5
The topological materials have attracted much attention for their unique electronic structure and peculiar physical properties. ZrTe5 has host a long-standing puzzle on its anomalous transport properties manifested by its unusual...
High-Resolution Three-Dimensional Spin- and Angle-Resolved Photoelectron Spectrometer using Vacuum Ultraviolet Laser Light
We describe a spin- and angle-resolved photoelectron spectroscopy (SARPES) apparatus with a vacuum-ultraviolet (VUV) laser (hν = 6.994 eV) developed at the Laser and Synchrotron Research Center at the Institute for Solid State Physics,...
ARPES Lab with Integrated Preparation Chamber
Research focuses on carbon-based composite functional materials, new energy storage materials and devices, and the preparation and modification of marine functional materials.more
Materials Innovation Platform (MIP) with MBE, NanoScan Lab, VT AFM and ARPES Lab
Research focuses on Magnetic Films and Spintronics, including antiferromagnet spintronics and multi-field control of magnetism.more
ARPES Lab with Lab10 MBE
Research focus on spintronics, quantum transport theory of graphene and mesoscopic nanosystems, and theoretical research on the topological effect and phase transition of condensed state systems.more
Materials Innovation Platform (MIP) for Epitaxial Quantum Materials
Research focus on controlled synthesis of epitaxial thin films and nanostructures, including: ferroelectrics, strongly correlated oxides, multiferroics, superconductors, thermoelectrics, photovoltaics, oxide catalysts, electronic/ionic conductors, and the characterisation of their functional properties.more
Materials Innovation Platform (MIP) with EVO-50 MBE, ARPES and LT Nanoprobe
The 2DCC-MIP is focused on advancing the synthesis of 2D materials within the context of a national user facility. The 2DCC is developing custom deposition tools with in-situ and real time characterisation and facilities for bulk growth of chalcogenide single crystals. Unique capabilities are also available to simulate growth kinetics through first principles and a reactive potential approach.more
DA30-L: Angle Resolved Electron Spectrometer
Since the launch in 2013, the DA30 family of analysers have revolutionised the field of ARPES. Using a fast electrostatic deflector concept, this well proven analyser can measure electrons in a full cone of 30 degrees opening angle. This opens up for band mapping of the full surface Brillouin zone without the need to rotate the sample and preserves incident and exit angles. The deflection capability ensures fixed spot shape and position on the sample and eliminates mechanical backlash, information depth variations, and angle dependent matrix element effects.
2D/3D Ferrum VLEED Detector for DA30-L
This 2D or 3D spin detection utilizes the exchange scattering mechanisms to be 50x more efficient than Mott schemes. One or two Ferrum VLEED detectors mount on a proprietary transfer lens with high speed switching between channels. The DA30-L's unique deflection mode directs any part of the full acceptance cone to the spin detectors without sample rotation. Integrating the Ferrum and the DA30-L creates the highest quality and most efficient spin ARPES measurements.