Effect of Co doping on the magnetotransport properties of La0.45Sr0.55MnO3 perovskite

Abstract

We investigated the magnetotransport properties of polycrystalline La0.45Sr0.55Mn1−xCoxO3 (0≤x≤0.15). Ferromagnetism is enhanced with the doping of Co ions in La0.45Sr0.55MnO3, but the antiferromagnetism is nearly destroyed in the low-temperature region. The Mn3+–Mn4+ double-exchange (DE) and Co2+–Mn4+ ferromagnetic (FM) superexchange interactions are mainly responsible for the magnetic properties of the doped system. With increased Co doping, the insulating properties and the magnetoresistance (MR) effect are simultaneously enhanced. This indicates that the Co doping strengthens both the Mn3+–Mn4+ DE and Co2+–Mn4+ FM superexchange interactions. The Co doping increases the disorder in the system, causing the MR effect to increase with decreasing temperature.

Synthesis, electronic and magnetic properties of the double B mixed perovskite series La0.5Sr0.5Mn1−xFexO3

“…In fact, the ionic size of Fe 3+ is 0.645Å whereas that of Mn 3+ is 0.64Å; hence the substitution of Fe 3+ should not introduce noticeable lattice distortion. Similar findings have been observed by other researchers also [8,24]. The twinned crystallization of the products obtained by hydrothermal synthesis was observed by SEM image shown in Fig.…”

“…The substitution of the Mn ions by other transition metal ion, such as Cr, Fe, Co and Ni, can give rise to important modifications in the magnetic and transport properties [3][4][5][6][7][8]. Among others, Fe is particularly interesting, because it does not cause considerable lattice distortion [9] due to close ionic radii of Fe 3+ and Mn 3+ [10], which is a special model to study the unique properties of manganites.…”

Magnetic interactions and spin-reversal mechanism in ErMn1-xCoxO3-δ samples

“…The effects of Co ionic substitutions in manganite compounds have been studied in the literature, and are still a controversial issue [21,22]. Starting from antiferromagnetic phases, it seems that cobalt substitutions in manganese sites induce ferromagnetism in a phase separation scenario, with two different types of superexchange interactions.…”

Magnetotransport and magnetoelastic effects in Co-doped La0.7Sr0.3MnO3 nanocrystalline perovskites

“…In LSMO with x ¼0.3, T C $ 380 K [15]; this promises well that the GVMS and CMR effects will take place in Co-doped LSMO around room temperature, appropriate for applications. Despite some previous research on Co-substituted LSMO studying their electrical, magnetic and magnetotransport properties [15][16][17][18][19][20][21], to date no report has been published on magnetoelastic properties of these compounds. So, in this work, we investigate the magnetostriction effects of La 0.7 Sr 0.3 Mn 1 À x Co x O 3 (LSMC x O) along with their magnetotransport properties.…”