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.

Prahallad Padhan

Department Of Physics

IN-PLANE DIRECTION

Out-of-plane

OUT-OF-PLANE DIRECTION

size effects

SrTiO

Stacking order

Structural distortions

Unit cells

Antiferromagnetism

Ferromagnetic materials

Magnetic couplings

Manganese oxide

Ruthenium compounds

Superlattices

Ferromagnetism

Fulltext

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IIT Madras

Size effect on magnetic coupling in all-ferromagnetic superlattices

Applied Physics Letters

The functional properties of oxide heterostructures depend on the interfaces accommodating ions, their spins, and structural mismatches. Here, by stabilizing tetragonal symmetry, we achieve the in-plane antiferromagnetic (AFM) ordering and dual-exchange bias in the superlattices consisting of two ferromagnets SrRuO3 (SRO) and PrMnO3 (PMO). The tetragonal symmetry of this superlattice system achieved after the octahedral rotations yield an elongation of the c-axis parameter with Ru-O-Mn bond angle close to 180°, induces an interfacial antiferromagnetic ordering, which is suppressed as the ferromagnetic (FM) ordering in the PMO layer increases. The 0.1 T in-plane cooling field (Hcool) leads to the shift (ca. -0.04 T) of minor hysteresis loop along the negative field axis due to the presence of -0.87 erg/cm2 AFM interfacial exchange coupling energy density (ERu,Mn) at 20 K. The exchange bias field (HEB) switches from negative to positive value with the increase in Hcool. For 5 T Hcool, the HEB is positive, but the ERu,Mn is -1.25 erg/cm2 for n ≤ 8 (n = number of unit cells of PMO) and 1.52 erg/cm2 for n ≥ 8. The HEB and its switching from negative to positive with the increase in Hcool are explained by the interplay of strong antiferromagnetic coupling energy and Zeeman energy at the interfaces. The results demonstrate that the SRO-PMO superlattice could be a model system for the investigation of the interfacial exchange coupling in functional oxides. © 2017 American Chemical Society.

ACS Applied Materials and Interfaces

Interfacial Antiferromagnetic Coupling and Dual-Exchange Bias in Tetragonal SrRuO3-PrMnO3 Superlattices

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

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.

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

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

Inverted hysteresis and giant exchange bias in La0.7Sr0.3MnO3/SrRuO3 superlattices

Physical Review Letters

Tailoring Magnetic Interlayer Coupling inLa0.7Sr0.3MnO3/SrRuO3Superlattices

Journal of Physics: Conference Series

Magnetic properties of high-pressure phase of CaRuO3with post-perovskite structure

Physical Review B

Strain induced x-ray absorption linear dichroism inLa0.7Sr0.3MnO3thin films

Journal	Applied Physics Letters
ISSN	00036951
Open Access	No