iMAT Lecture: Estia, small sample polarized neutron reflectometer at ESS and complex magnetism in manganite heterostructures

Speaker Artur Glavic (PSI/ESS).

05.12.2017 | Hazel Reardon

Dato fre 08 dec
Tid 12:00 13:00
Sted Department of Chemistry, AUD VI (1510-213)

Abstract
In the first part of the talk I will present the Estia instrument that is being build for the European Spallation Source in Lund, Sweden. This next generation polarized neutron reflectometer will allow reflectometry from tiny samples down to 1x1mm² and sub-second time resolution investigations on moderate size samples of 10x10mm². To accomplish this the instrument uses, in addition to the high flux available at the ESS, the focusing reflectometry concept which allows specular reflectivity with a divergent beam to greatly increase the neutron flux on the sample. Estia will employ the Selene neutron guide concept to image a Virtual Source slit onto the sample, increasing the relative amount of usable neutrons and assuring good signal to background ratio. This optics requires a high degree of precision for the guide sections which is one of the major challenges for the engineering design that is addressed with active adjustment components and interferometric feedback.

The second part will focus on neutron reflectometry and diffraction studies on thin heterostructures of NdMnO3 and SrMnO3. We could show that these materials, when grown with specific thicknesses, form a system of ferromagnetic and antiferromagnetic layers that are directly coupled at the insterface. In addition to the implications for the fundamental understanding of magnetic couplings at oxide interfaces this method could be used to allow magnetic fields to couple to antiferromagnetic multiferroics in magnetoelectric devices.

Medarbejdere
79541 / i31