English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

The exchange bias (EB) phenomenon has received considerable attentionbecause of its important applications in magnetic storage devices. Of particular interestare the EB properties of colossal magnetoresistance (CMR) compositionally modulatedstructures consisting of antiferromagnetic (AF) and ferromagnetic (FM) (La,Ca)MnO3 layersbecause manganites are strongly correlated electron systems, in which the magnetic,electronic and crystal structures interact strongly with each other. Complementary x-raysynchrotron radiation diffraction (XRD) and resonant scattering (RXS) measurements wereperformed at the Mn K-edge between 10 and 300 K in order to analyze the effect of epitaxialstrain and tetragonal lattice distortions on the exchange bias (EB) mechanism observed in[La2/3Ca1/3MnO3(FM)/La1/3Ca2/3MnO3(AF)]15 multilayers below a blocking temperature, TB, of80 K. XRD measurements showed that the c/a axial ratio, an indication of the tetragonallattice distortion in pseudocubic lattice settings, reaches its maximum at the onset of theEB effect and the corresponding structural correlation length varies substantially at theonset of TB. The in-plane lattice parameter a at TB is close to the bulk lattice parametersof the AF layers, thus indicating that the EB effect is related with the accommodation ofstrain inside the FM and AF layers. RXS measurements revealed that such anisotropic latticestrains force the MnO6 octahedral sites into a ferrodistortive (FD) alignment, where the FDsupercell coincides with the unit cell of the crystalline lattice. The RXS intensitydifference signal exhibits a main-edge feature and a post-edge feature at 6.57 keV thatscales linearly with temperature and the c/a ratio up to 80 K. The disappearance of thepost-edge feature above 80 K(=TB) may signify a rearrangement of Mn-O-Mn bonding angles dueto strain-driven effects at the FM/AF interfaces, inducing disorder in FD octahedral tiltordering which may pin the local distortions below the TB.

Επίδραση των ελαστικών τάσεων επιταξίας στο μηχανισμό της μαγνητικής πόλωσης ανταλλαγής της πολυστρωματικής δομής [La2/3Ca1/3MnO3/La1/3Ca2/3MnO3]15