Past colloquia and seminars


Observation of Mermin-Wagner behavior in LaFeO3/SrTiO3 superlattices

Academic or specialist Seminar

Two-dimensional magnetic materials attract a lot of attention since they potentially exhibit new magnetic properties due to, e.g., strongly enhanced spin fluctuations. However, the suppression of the long-range magnetic order in two dimensions due to long-wavelength spin fluctuations, as suggested by the Mermin-Wagner theorem, has been questioned for finite-size laboratory samples. We study the magnetic properties of a dimensional crossover in superlattices composed of the antiferromagnetic LaFeO3 and SrTiO3 that, thanks to their large lateral size, allowed examination using a sensitive magnetic probe — muon spin rotation spectroscopy. We show that the iron electronic moments in superlattices with 3 and 2 monolayers of LaFeO3 exhibit a static antiferromagnetic order. In contrast, in the superlattices with single LaFeO3 monolayer, the moments do not order and fluctuate to the lowest measured temperature as expected from the Mermin-Wagner theorem. Our work shows how dimensionality can be used to tune the magnetic properties of ultrathin films.

When? 10.06.2024 14:00
Where? PER 08 2.73
Chemin du Musée 3
1700 Fribourg
speaker Adam Dubroka
Department of Condensed Matter Physics, Masaryk University
Invité par Prof. Bernhard
Contact Département de Physique, Groupe Bernhard
Prof. Christian Bernhard
Chemin du Musée 3
1700 Fribourg