Study of Pr1−xMn1+xO3 perovskites

Expansion of multifunctionality in off-stoichiometric manganite using post-annealing and high pressure: physical and electrochemical studies

Prospects for the use of manganites in various areas of modern technologies require comprehensive studies of their physical and chemical properties. La0.9Mn1.1O3 (LMO) ceramics have been synthesized at annealing temperature...

Ultrathin Scale Tailoring of Anisotropic Magnetic Coupling and Anomalous Magnetoresistance in SrRuO3-PrMnO3 Superlattices

A strong perpendicular magnetocrystalline anisotropy (PMA) in antiferromagnetically coupled SrRuO₃(17 uc (unit cell))/PrMnO₃( n uc) superlattices effectively reconstructs the interfacial spin ordering. The occurrence of significant anisotropic interfacial antiferromagnetic coupling between the Ru and Mn ions is systematically tuned by varying the PrMnO₃ layer thickness in ultrathin scale from 3 to 12 uc, which is associated with a rise in PMA energy from 0.28 × 10⁶ to 1.60 × 10⁶ erg/cm³. The analysis using the Stoner-Wohlfarth model and density functional theory confirm that the exchange anisotropy is the major contribution to the PMA. The superlattices with PrMnO₃ layer thickness ≥7 uc exhibit the tunneling-like transport of Ru 4d electrons, which is rather expected in the stronger antiferromagnetically coupled superlattices with thinner PrMnO₃ layer. Tunneling-like transport at thicker spacer layer in the SrRuO₃-PrMnO₃ superlattice system is an unique feature of two ferromagnet-based superlattices. Our investigations show that the technologically important interfacial magnetic coupling, PMA, and tunneling magnetoresistance could be achieved in a periodically stacked bilayer and can be precisely manipulated by the size effect in ultrathin scale.

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

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 (H_cool) 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 (E_Ru,Mn) at 20 K. The exchange bias field (H_EB) switches from negative to positive value with the increase in H_cool. For 5 T H_cool, the H_EB is positive, but the E_Ru,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 H_EB and its switching from negative to positive with the increase in H_cool 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.

Synthesis, structure and magnetic properties of (Eu1−xMnx)MnO3−δ

The solid solution (Eu_1−xMn_x)MnO_3−δ (0 ≤ x ≤ 0.126) has been synthesized using a conventional solid-state method.

Copper doped EuMnO3: synthesis, structure and magnetic properties

Solid solution EuMn_1−xCu_xO_3−δ (0 ≤ x ≤ 0.316) crystallizes in the space group Pnma and shows magnetic transitions from about 52 to 20 K.