2 research outputs found
Magnetic Properties of Pr0.7Ca0.3MnO3/SrRuO3 Superlattices
High-quality Pr0.7Ca0.3MnO3/SrRuO3 superlattices were fabricated by pulsed
laser deposition and were investigated by high-resolution transmission electron
microscopy and SQUID magnetometry. Superlattices with orthorhombic and
tetragonal SrRuO3 layers were investigated. The superlattices grew coherently;
in the growth direction Pr0.7Ca0.3MnO3 layers were terminated by MnO2- and
SrRuO3 layers by RuO2-planes. All superlattices showed antiferromagnetic
interlayer coupling in low magnetic fields. The coupling strength was
significantly higher for orthorhombic than for tetragonal symmetry of the
SrRuO3 layers. The strong interlayer exchange coupling in the superlattice with
orthorhombic SrRuO3 layers led to a magnetization reversal mechanism with a
partially inverted hysteresis loop.Comment: 12 pages, 4 figure
Orthorhombic to tetragonal transition of SrRuO3 layers in Pr0.7Ca0.3MnO3/SrRuO3 superlattices
High-quality Pr0.7Ca0.3MnO3/SrRuO3 superlattices with ultrathin layers were
fabricated by pulsed laser deposition on SrTiO3 substrates. The superlattices
were studied by atomically resolved scanning transmission electron microscopy,
high-resolution transmission electron microscopy, resistivity and
magnetoresistance measurements. The superlattices grew coherently without
growth defects. Viewed along the growth direction, SrRuO3 and Pr0.7Ca0.3MnO3
layers were terminated by RuO2 and MnO2, respectively, which imposes a unique
structure to their interfaces. Superlattices with a constant thickness of the
SrRuO3 layers, but varying thickness of the Pr0.7Ca0.3MnO3 layers showed a
change of crystalline symmetry of the SrRuO3 layers. At a low Pr0.7Ca0.3MnO3
layer thickness of 1.5 nm transmission electron microscopy proved the SrRuO3
layers to be orthorhombic, whereas these were non-orthorhombic for a
Pr0.7Ca0.3MnO3 layer thickness of 4.0 nm. Angular magnetoresistance
measurements showed orthorhombic (with small monoclinic distortion) symmetry in
the first case and tetragonal symmetry of the SrRuO3 layers in the second case.
Mechanisms driving this orthorhombic to tetragonal transition are briefly
discussed.Comment: 23 pages, 12 figure