FeSe films grown by DC sputtering: thickness dependence of the physical properties

date

25.04.2018 

time

09:45 AM - 10:45 AM 

speaker

Ph.D. María Victoria Ale Crivillero 

affiliation

Low Temperature Lab Bariloche, Argentina 

language

en 

main topic

Materials: Superconductors, Magnetic Materials, Nano Structures

subtopics

Physics: Condensed Matter (incl. Soft, Solid)

host

Ines Firlle 

abstract

Among the iron-based superconductors, iron selenide stands out as a rich system for studying new emergent phenomena. Particular interest has been triggered by the multi-band electronic structure and the nematic phase transition without magnetic order at 90K. The reports of superconductivity above 65K in extremely thin FeSe films has also triggered great enthusiasm. In this context, fundamental questions concerning interfacial effects are still open.
In this talk, I will discuss the thickness effects in the electronic properties of FeSe films grown by DC magnetron sputtering [1]. We report a superconductor-insulator transition (SIT) by reducing the thickness as a general feature of sputtered FeSe films. Similar results have been interpreted in terms of a continuous quantum phase transition induced by disorder [2]. In our samples, this scheme becomes inappropriate due to the evolution of the structural properties and morphology. In the limit of textured thick films, the critical temperature takes values slightly higher than that expected for bulk FeSe, Tc~12K. The electronic structure in the normal state was explored by performing magneto-transport and Hall experiments, finding features associated with nematic fluctuations despite the presence of disorder.
[1] M.V. Ale Crivillero et al.; arXiv:1801.08489 (2018).
[2] R. Schneider et al.; Phys. Rev. Lett.108, 257003 (2012).

 

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