Instrumentation

The maestro endstation consists of several connected endstations:

1) microARPES (µARPES): 60x10 µm probe size (can go to 10x10 by aperturing down incident beam), currently routinely achieving 8 meV resolution down to ~15K temperature. Annealing of samples to > 2000C is also possible.

2) LEEM/PEEM: we can image the bandstructure at a single point, down to 3µm spatial resolution. We can also full-field image the sample with “bandstructure contrast” (a bit like dark field imaging in a TEM, where we put a filter (about 0.5 eV by about 1/2 degree) on a small section of the ARPES bandmap) down to <40nm resolution. sample temperature is 120K when using LN₂ cooling. This machine uses a commercial sample holder, not really intended for low temperature, which we would like to replace with our own design some day.

In 2017, we will be installing the LEEM upgrade, which is expected to improve the spatial resolution down to about 4 nm. We will also be upgrading the manipulator, to be able to take omicron-type sample holders.

3) nanoARPES (nARPES): currently under testing. Currently, we achieved < 150 nm spatial resolution. It will go down to 50 nm and 10 meV energy resolution in principle; first year we will be only at room temperature but we hope for 20-40K base temperature eventually. Visit the nanoARPES page for commissioning results and other news.

We also have extensive sample prep and characterization stations on-line:

4) Glovebox: we have a 1.2meter single user glovebox connected to our UHV system, so samples can be prepared/mounted without H₂O or O₂ exposure

5) MBE-1: Surface preparation chamber with sputter, LEED, RHEED, ESCA (PHI 150mm Analyzer), and many ports for installation of evaporators. Typically used for metal and semiconductor growth, and surface cleaning of crystals.

6) MBE-2: Currently under construction, will feature ESCA/ARUPS (SES-200 Analyzer) with simultaneous 4-point transport probe

7) PLD: Currently operational, used for oxide growth, and other systems such as FeSeTe.

8) Scanning probe: currently an AFM is planned, with possible upgrade path to STM.

These endstations are connected by a UHV sample transporter system:

9) "MART" (Maestro Area Rapid Transit), an automated highway for samples, with storage capacity for more than 250 sample holders. There is a common sample holder scheme so that samples can be freely moved between PEEM, nARPES, and µARPES endstations as well as all of the growth and characterization chambers.