Superlattices consist of two ferromagnets La0.7Sr 0.3MnO3 (LSMO) and SrRuO3 (SRO) were grown in (110)-orientation on SrTiO3 (STO) substrates. The x-ray diffraction and Raman spectra of these superlattices show the presence of in-plane compressive strain and orthorhombic structure of less than 4 u.c. thick LSMO spacer, respectively. Magnetic measurements reveal several features including reduced magnetization, enhanced coercivity, antiferromagnetic coupling, and switching from antiferromagnetic to ferromagnetic coupling with magnetic field orientations. These magnetic properties are explained by the observed orthorhombic structure of spacer LSMO in Raman scattering which occurs due to the modification in the stereochemistry of Mn at the interfaces of SRO and LSMO. © 2014 AIP Publishing LLC.

Prahallad Padhan

Department Of Physics

Antiferromagnetic coupling

Antiferromagnetics

ENHANCED COERCIVITY

Ferromagnetic coupling

Ferromagnets

In-plane compressive strain

MAGNETIC FIELD ORIENTATIONS

Orthorhombic structures

Ferromagnetic materials

Ferromagnetism

Magnetization

Manganese oxide

Strontium titanates

Superlattices

X ray diffraction

Raman scattering

Fulltext

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IIT Madras

Applied Physics Letters

A series of superlattices consisting of 15 bilayers of ferromagnetic La0.7Sr0.3MnO3 (LSMO) and SrRuO3 (SRO) were grown with either stacking order on (1 1 1) oriented SrTiO3 (STO) substrates using the pulsed laser deposition technique. The Raman spectra of these superlattices show the existence of rhombohedral and orthorhombic crystal structures of LSMO in (111)STO/[11-unit cell (u.c.) LSMO/n-u.c. SRO]X15 superlattices with n = 2 and 3. Interestingly, the Raman spectra of (1 1 1)STO/[11-u.c. SRO/n-u.c. LSMO]X15 superlattices with n = 2 and 3 show only the orthorhombic structure of LSMO. The (1 1 1)STO/[11-u.c. LSMO/n-u.c. SRO]X15 superlattices exhibit enhanced magnetization with weak antiferromagnetic coupling whereas reduced magnetization with strong antiferromagnetic coupling is observed in (1 1 1)STO/[11-u.c. SRO/n-u.c. LSMO]X15 superlattices. The observed magnetic properties of these superlattices can be explained by the interfacial structural coupling, as evident from their Raman spectra which suggest a modification in the stereochemistry of Mn at the interfaces. © 2016 IOP Publishing Ltd.

Journal of Physics Condensed Matter

Effect of La0.7Sr0.3MnO3 crystal structures on magnetization of (1 1 1) oriented La0.7Sr0.3MnO3-SrRuO3 superlattices

Magnetic properties of a series of (La0.7Sr 0.3MnO3/SrRuO3) superlattices, where the SrRuO3 layer thickness is varying, are examined. A room-temperature magnetocaloric effect is obtained owing to the finite size effect which reduces the TC of La0.7Sr0.3MnO3 layers. While the working temperature ranges are enlarged, -ΔSM max values remain similar to the values in polycrystalline La 0.7Sr0.3MnO3. Consequently, the relative cooling powers are significantly improved, the microscopic mechanism of which is related to the effect of the interfaces at La0.7Sr 0.3MnO3/SrRuO3 and higher nanostructural disorder. This study indicates that artificial oxide superlattices/multilayers might provide an alternative pathway in searching for efficient room-temperature magnetic refrigerators for (nano) micro-scale systems. © 2011 IOP Publishing Ltd Printed in the UK &amp; the USA.

Magnetocaloric effect and improved relative cooling power in (La 0.7Sr0.3MnO3/SrRuO3) superlattices

The switching of ferromagnetic-to-antiferromagnetic coupling of magnetization in the superlattices consisting of two ferromagnetic metals La 0.7Sr 0.3MnO 3 (LSMO) and SrRuO 3 (SRO) grown on (001) oriented SrTiO 3 has been observed by changing the orientation of the field from out-of-plane to in-plane direction. Such switching of magnetic coupling strongly depends on the stacking order of La 0.7Sr 0.3MnO 3 and SrRuO 3 layers in the superlattice of 20 unit cell (u.c.)/n (=3 or 5) u.c. thickness configuration. This is explained by the structural distortion in the MnO 6 and RuO 6 octahedra along the out-of-plane direction due to the observed stress. © 2011 American Institute of Physics.

Size effect on magnetic coupling in all-ferromagnetic superlattices

We exploit the magnetic interlayer coupling in La0.7 Sr0. 3 MnO3/SrRuO3 superlattices to realize a crossover between inverse and conventional magnetic entropy changes. Our data reveal a strong anisotropic nature of the magnetocaloric effect due to the magnetic anisotropy of the superlattice. Therefore, artificial superlattices built from ferromagnetic materials that can be used to alter the magnetic structure as well as the magnetic anisotropy, could also be utilized for tuning the magnetocaloric properties, which may open a constructive approach for magnetic refrigeration applications. © 2010 American Institute of Physics.

Anisotropic magnetocaloric effect in all-ferromagnetic (La0.7 Sr0.3 MnO3/SrRuO3) superlattices

Physical Review Letters

High-Temperature Magnetic Insulating Phase in UltrathinLa0.67Sr0.33MnO3Films

Nature Communications

Surface symmetry-breaking and strain effects on orbital occupancy in transition metal perovskite epitaxial films

Raman spectra and magnetization of all-ferromagnetic superlattices grown on (110) oriented SrTiO3

Journal	Data powered by TypesetApplied Physics Letters
Publisher	Data powered by TypesetAmerican Institute of Physics Inc.
ISSN	00036951
Open Access	No