SITTA

Variable-Temperature STM for Spectroscopy

Prof. Amadeo L. Vázquez de Parga

People - Publications list - Image Gallery

The Ultra High Vacuum (UHV) chamber contains a variable temperature Scanning Tunneling Microscope (STM), a rear-view low energy electron diffraction optics (LEED), Auger Spectroscopy a fast-load entry system and facilities for ion sputtering, and depositing different materials on the STM tip and sample.

With the Scanning Tunneling Microscope (STM) is possible to characterize the surface morphology to understand crystal growth processes and atomic diffusion on surfaces but also gives us the possibility to study locally the electronic structure of surfaces. The combination of non local techniques like LEED with a local probe one, like STM is a powerful combination that allow us to study a great variety of systems.

With this experimental setup we are able to deposit materials on the surfaces at different temperatures while taking STM images and also do tunneling spectroscopy (STS) experiments at low temperatures.

This will allow us to tackle new problems like, surface diffusion, the atomic mechanism of surfactants, the study of catalytic processes, study of the interaction of surface state electrons with different obstacles on surfaces and the formation of standing waves (SW), confinement of electrons in one dimensional systems, visualization in real space of quantum well states (QWS), charge density waves (CDW) on surfaces, tunneling spectroscopy at different temperatures on magnetic samples or superconductor samples, etc.

Research Topics

• Characterization of STM tips density of states and its influence in tunneling spectroscopy (STS).
• Electron confinement on surfaces:
  • Interaction of Cu(111) surface states with steps.
  • Quantum Well States on Lead nanoislands grown on Cu(111).
• Injection of ballistic electrons in magnetic superlattices (Spintronics).
• Magic heights dictated by the electronic structure.
• Effect of surfactants on crystal growth
  • Self-surfactant effect on the Fe/Au(001) system
  • Influence of surfactants on atomic diffusion.
• Intermixing mechanism in heteroepitaxy
• Bimetallic surfaces.
• Contrast of atomic adsorbates in STM
• Spin-polarized STM