Direct observation of temperature dependent magnetic domain structure of the multiferroic La0.66Sr0.34MnO3/BiFeO3 bilayer system by x-ray linear dichroism- and x-ray magnetic circular dichroism-photoemission electron microscopy

Low-thickness La0.66Sr0.34MnO3 (LSMO)/BiFeO3 (BFO) thin film samples deposited on SrTiO3 were imaged by high resolution x-ray microscopy at different temperatures. The ultra-thin thickness of the top layer allows to image both the ferromagnetic domain structure of LSMO and the multiferroic domain structure of the buried BFO layer, opening a path to a direct observation of coupling at the interface on a microscopic level. By comparing the domain size and structure of the BFO and LSMO, we observed that, in contrast to LSMO single layers, LSMO/BFO multilayers show a strong temperature dependence of the ferromagnetic domain structure of the LSMO. Particularly, at 40 K, a similar domain size for…

Exchange coupling in the correlated electronic states of amorphous GdFe films

The bulk sensitivity of hard x-ray photoelectron spectroscopy in combination with circularly polarized radiation of the P09 beamline at PETRA III enables the investigation of the magnetic properties of capped films. We have determined the temperature dependence of the magnetic circular dichroism in the Fe 2$p$ and in the Gd 3$d$ states in amorphous GdFe films. The magnetic dichroism reflects the stronger temperature dependence of Gd moments compared to Fe moments in agreement with mean-field models. We resolved the exchange split Gd 3${d}_{5/2}$ substates and found a significant temperature dependence of the splitting which is attributed to a temperature dependent part of the exchange energ…

c-Axis tunneling in YBa2Cu3O7-\delta/PrBa2Cu3O7-\delta superlattices

In this work we report c-axis conductance measurements done on a superlattice based on a stack of 2 layers YBa2Cu3O{7-\delta} and 7 layers PrBa2Cu3O{7-\delta} (2:7). We find that these quasi-2D structures show no clear superconducting coupling along the c-axis. Instead, we observe tunneling with a gap of \Delta_c=5.0\pm 0.5 meV for the direction perpendicular to the superconducting planes. The conductance spectrum show well defined quasi-periodic structures which are attributed to the superlattice structure. From this data we deduce a low temperature c-axis coherence length of \xi_c=0.24\pm 0.03 nm.

Electrical detection of the spin reorientation transition in antiferromagnetic Tm Fe O 3 thin films by spin Hall magnetoresistance