logo icmab ochoa 02 01 logo icmab ochoa 02 01
  • NEWS

Instability and Surface Potential Modulation of Self-Patterned (001)SrTiO3 Surfaces

2015 11 02 9 33 47

Lucía AballeSonia MatencioMichael FoersterEsther BarrenaFlorencio SánchezJosep Fontcuberta, and Carmen Ocal*;  
Chem. Mater., 2015, 27 (18), pp 6198–6204;  
DOI: 10.1021/acs.chemmater.5b00661

The (001)SrTiO3 crystal surface can be engineered to display a self-organized pattern of well-separated and nearly pure single-terminated SrO and TiO2 regions by high temperature annealing in oxidizing atmosphere. By using surface sensitive techniques we have obtained evidence of such a surface chemical self-structuration in as-prepared crystals and unambiguously identified the local composition. The contact surface potential at regions initially consisting of majority single terminations (SrO and TiO2) is determined to be Φ(SrO) < Φ(TiO2), in agreement with theoretical predictions, although the measured difference ΔΦ ≤ 100 meV is definitely below calculations for ideally pure single-terminated SrO and TiO2 surfaces. These relative values are maintained if samples are annealed in UHV up to 200 °C. Annealing in UHV at higher temperature (400 °C) preserves the surface morphology of self-assembled TiO2 and SrO rich regions, although a non-negligible chemical intermixing is observed. The most dramatic consequence is that the surface potential contrast is reversed. It thus follows that electronic and chemical properties of (001)SrTiO3 surfaces, widely used in oxide thin film growth, can largely vary before growth starts in a manner strongly dependent on temperature and pressure conditions.

See more posts on ICMAB related to: Materials for information science and electronics

Related Topics: Materials for information science and electronics

Also on ICMAB...

  • Imaging how magnetism goes surfing

    01 September 2017 521 hit(s)

    Using ALBA’s synchrotron light, researchers have been able to visualise deformation (sound) waves in crystals and measured the effect on nanomagnetic elements. The study, published today in Nature Communications, uses the accelerators’ time structure to record time resolved images with a resolution of 80 picoseconds. The methodology offers a new approach for analysing dynamic strains in other research fields: nanoparticles, chemical reactions, crystallography, etc.
  • ICMAB participates in the Barcelona Science Festival, from 15th to 28th May

    17 May 2017 905 hit(s)

    During two whole weeks, Barcelona is science! The most traditional event is the "Festa de la Ciència" (Science party), this year at its 11th edition, at the Parc de la Ciutadella, which will take place during the weekend 27th-28th May.
  • Esther Barrena and Ana Pérez at the PINT OF SCIENCE Barcelona on May 16th

    11 May 2017 1048 hit(s)

    Pint of Science is one of the most popular science outreach activities in Spain, and is back in Barcelona during May 15th-17th, this year in its 3rd edition.

Search