Unraveling the impact of nonmagnetic Sc substitution on the magnetic properties of La₂NiMnO₆ double perovskite

Abstract

The structural, electronic, and magnetic properties of a sol-gel prepared series of La2Ni1−x Sc x MnO6 compounds have been extensively studied using x-ray diffraction, x-ray absorption near edge structure, and dc magnetization techniques, respectively. The entire series was isostructural and exhibited the La2NiMnO6 double perovskite P21/n monoclinic structure. The nonmagnetic Sc3+ substitution led to the evolution of competing magnetic phases in La2Ni1−x Sc x MnO6. The substitution also caused an increase in lattice parameters, cell volume, and bond lengths. Consequently, Sc3+ dilution resulted in a dramatic decrease in Curie temperature, suggesting a reduction in the strength of the Ni2+–O2−–Mn4+ superexchange ferromagnetic interaction. The Sc3+ substitution generated antisite defects, which significantly suppressed the saturation magnetization of the system. The competing magnetic interactions observed in the La2Ni1−x Sc x MnO6 system are discussed in terms of cation disorder, cation valances, and changes in the bond lengths/angles, caused by the Sc3+ substitution.

Substitutional effect of Mg2+ on structural and magnetic properties of La2MgxNi1‐xMnO6 double‐perovskite thin films

“…These advantages have enormously boosted them in an upsurge application in spintronic devices. [1][2][3][4][5][6][7][8][9][10][11][12] Among the multitudinous double-perovskites, La 2 NiMnO 6 (abbreviated as LNMO) double-perovskite has beguiled great interest due to its high Curie point near room temperature. 4,[13][14][15][16][17][18][19] Particularly, the magnetic properties of LNMO thin films can be flexibly regulated by means of varying deposition parameters or employing the appropriate substrate wafers.…”

“…Thanks for the significant coupling effect between lattice, charge, spin and orbit of different ions at multiple B‐sites in double‐perovskite compounds, they exhibit more abundant compositional variation as well as physical property tunability than the traditional single‐perovskites. These advantages have enormously boosted them in an upsurge application in spintronic devices 1–12 . Among the multitudinous double‐perovskites, La 2 NiMnO 6 (abbreviated as LNMO) double‐perovskite has beguiled great interest due to its high Curie point near room temperature 4,13–19 .…”

Cluster spin-glass-like dynamics in Mn-rich La2Ni0.5Mn1.5O6 ferromagnetic insulator

“…Ferromagnetism in this compound is governed by the superexchange mechanism between the half-filled e g orbitals of Ni 2+ and the adjoining empty e g orbitals of Mn 4+ cations [15,16]. The magnetic, electronic, and transport properties of the compound are extremely sensitive to the ordering of Ni 2+ and Mn 4+ cations at two B-sites and can be modified by doping at A [17,18] or B [19][20][21] sites. It has been shown that the crystallographic structures, Curie temperatures, and saturation magnetizations of double perovskites can be well-tuned by controlling the ratio of the two B-site cations [6,[22][23][24].…”