Magnetic, magnetocaloric and thermoelectric properties of nickel doped manganites

Abstract

In this study, we investigate structural, magnetic, magnetocaloric and thermoelectric properties of La 0.7 Sr 0.3 Mn 1-x Ni x O 3 compounds with 0.025≤x≤0.125. X-ray diffraction analysis shows the structure transformation from the R-3c rhombohedral to the Pbnm orthorhombic structure with Ni 2+ doping at x≥0.075 composites. The dc thermal magnetization measurements reveal the monotonic decrease in both Curie temperature and magnetization values with Ni 2+ addition. The change in magnetic properties of the studied system is correlated to the ferromagnetism suppression and the antiferromagnetism promotion according to some cooperative intrinsic and extrinsic factors. Results show that Ni 2+ doping affects the magnetocaloric properties, where it shifts the maximum value of the magnetic entropy change towards lower temperatures with relative cooling power of 88, 105, 47 J/kg for x=0.025, 0.075 and 0.125 composites, respectively. Moreover, it is observed that Ni 2+ doping increases the absolute value of Seebeck coefficient and decreases hole conduction interval,

Effect of Ni Substitution to Structure and Morphology of Ca_0.9La_0.05Bi_0.05Mn_1-xNi_xO₃ by Sol-Gel Method

“…It is shown that the average crystallite size decreases with increasing Ni substitution, the decreases of the crystallite size may be due to an incorporation of Ni dopants at the manganite host lattice. This result is consistent with the result of Ni substitution on other perovskite manganite [3,5].…”

“…One of the approaches to improve its thermoelectric performance is to substitute one or more metal ion into the host lattice. Ni substitution on perovskite manganese La0.7Sr0.3Mn1-xNixO3 with x = 0.025, 0.05, 0.075, 0.01, and 0.0125 proved to increase the Seebeck coefficient of the samples [3]. On the other hand, the Ca09La0.05Bi0.05MnO3 seems to have the highest Seebeck coefficient among other perovskite manganese Ca09La1-xBixMnO3 with x = 0, 0.025, 0.05, 0.075, and 0.01 [4].…”

Improvement of thermoelectric properties of lanthanum cobaltate by Sr and Mn co-substitution

“…The idea of double substitutions was introduced with a view that substitution at La site will increase the electrical conductivity and that at Co site enhances Seebeck coefficient [38]. There have also been attempts to investigate the effect of single-site substitution and co-substitution on TE properties in rare earth manganite systems [34][35][36][37]. Studies on thermal transport behavior at high temperatures is worth exploring in samples with co-substitution.…”

Study of Magnetoresistance Effect and Magnetic Properties of La_0.67Sr_0.33Mn_1-<i>x</i>Ni<i>_x</i>O₃ (x = 0 and 0.2) Material Prepared by Sol-Gel Method

“…When LSMO was doped by Ni on Mn site, the possible bonds between anion and cation that may occur in the samples are Ni 2+ -O -Ni 2+ , Mn 3+ -O -Ni 2+ , Mn 4+ -O -Ni 2+ , Mn 3+ -O -Mn 3+ , Mn 4+ -O -Mn 4+ and Mn 3+ -O -Mn 4+ . To fulfil Hund's rule, spins in Mn 3+ -O -Mn 4+ bond are arranged in parallel and contributed to the ferromagnetic state [7,8], while spins in Mn 3+ -O -Ni 2+ , Mn 4+ -O -Mn 4+ and Ni 2+ -O -Ni 2+ bonds are arranged as antiferromagnetic (AF) [8,9]. The scheme of cation-anion-cation interaction shown in Fig.…”