Journal ArticleDOI
Structural and magnetic inhomogeneities, phase transitions, 55 Mn nuclear magnetic resonance, and magnetoresistive properties of La 0.6 − x Nd x Sr 0.3 Mn 1.1 O 3-δ ceramics
A. V. Pashchenko,A. V. Pashchenko,V. P. Pashchenko,V. K. Prokopenko,Yu. F. Revenko,N. G. Kisel,V. I. Kamenev,A. G. Sil’cheva,N. A. Ledenev,N. A. Ledenev,V. V. Burkhovetskii,Georgiy Levchenko +11 more
TLDR
In this paper, an analysis of the X-ray diffraction, resistive, magnetic (χac, 55Mn NMR), magnetoresistive and microscopic methods has been carried out to investigate the structure, lattice imperfection, and properties of ceramic samples.Abstract:
The structure, lattice imperfection, and properties of ceramic samples La0.6 − x
Nd
x
Sr0.3Mn1.1O3-δ (x = 0–0.4) have been investigated using the X-ray diffraction, resistive, magnetic (χac, 55Mn NMR), magnetoresistive and microscopic methods. It has been shown that there is a satisfactory agreement between the concentration decrease in the lattice parameters a of the rhombohedral (x = 0, 0.1, 0.2) and cubic (x = 0.3, 0.4) perovskite structures and the average ionic radii $$\bar R$$
for the lattice containing anion vacancies, cation vacancies, and nanostructured clusters with Mn2+ ions in A-positions. With an increase in the neodymium concentration x, the vacancy-type imperfection increases, the cluster-type imperfection decreases, the temperatures of metal-semiconductor phase transition T
ms and ferromagnetic-paramagnetic phase transition T
C decrease, and the content of the ferromagnetic phase decreases. The anomalous hysteresis is associated with the appearance of unidirectional exchange anisotropy induced in a clustered perovskite structure consisting of a ferromagnetic matrix and a planar antiferromagnetic cluster coherently coupled with it. An analysis of the asymmetrically broadened 55Mn NMR spectra has revealed a high-frequency electronic double exchange (Mn3+-O2−-Mn4+) ↔ (Mn4+-O2−-Mn3+) and an inhomogeneity of the magnetic and charge states of manganese due to the heterogeneous environment of the manganese ions by other ions and defects. The observed changes in the resonant frequency and width of the resonance curve are caused by changes in the ratio Mn3+/Mn4+ and magnetic inhomogeneity. An increase in the neodymium concentration x leads to a decrease in the ferromagnetic phase content determined from the dependences 4πNχac(T) and the 55Mn NMR curves. The phase diagram characterizes an interrelation between the composition, the imperfection of the structure, and the transport, magnetic, and magnetoresistive properties of lanthanum neodymium manganite perovskites. It has been found that there is a correlation between the imperfection, magnetic inhomogeneity, coercive force, and magnetoresistance effect exhibited by the perovskite structure.read more
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Role of structure imperfection in the formation of the magnetotransport properties of rare-earth manganites with a perovskite structure
A. V. Pashchenko,A. V. Pashchenko,V. P. Pashchenko,V. K. Prokopenko,Vitalii Turchenko,Yu. F. Revenko,Anton S. Mazur,V. Ya. Sycheva,N.A. Liedienov,V. G. Pitsyuga,Georgiy Levchenko +10 more
TL;DR: The structure, the structure imperfection, and the magnetoresistance, magnetotransport, and microstructure properties of rare-earth perovskite La 0.3Ln0.3Sr0.1O3-δ manganites are studied by X-ray diffraction, thermogravimetry, electrical resistivity measurement, magnetic, 55Mn NMR, magnetoregressive measurement, and scanning electron microscopy as discussed by the authors.
Journal ArticleDOI
Effect of annealing environments on structural and electrical properties of La0.5Nd0.5MnO3 manganites
Bhagyashree Udeshi,Keval Gadani,Keval Gadani,K.N. Rathod,Hetal Boricha,V.G. Shrimali,Sapana Solanki,Alpa Zankat,V.S. Vadgama,Manan Gal,Davit Dhruv,A.D. Joshi,R. K. Trivedi,P.S. Solanki,Nikesh A. Shah +14 more
TL;DR: In this article, structural and electrical properties of rare earth La 0.5Nd0.5MnO3 (LNMO) manganites have been studied under the effect of synthesis environments.
Journal ArticleDOI
Effect of manganese stoichiometry at B-site on magneto-transport and magnetic properties of La0.67Sr0.33MnO3manganites
TL;DR: In this paper , a series of manganites with compositional formula La0.67Sr0.33Mn1±xO3 (where x = 0, 0.05 and 0.1) was synthesized by oxalate precursor method.
Journal ArticleDOI
Effect of Y doping on transport properties of La0.8Sr0.2MnO3 polycrystalline ceramics
TL;DR: In this paper, La0.8-xYxSr0.2MnO3 (LYSMO) polycrystalline ceramics were prepared by means of sol-gel technique using methanol as solvent.
Journal ArticleDOI
Expansion of the multifunctionality in off-stoichiometric manganites using post-annealing and high pressure: physical and electrochemical studies.
Zhi-Wei Gong,Wei Xu,N.A. Liedienov,Denys S. Butenko,Igor V. Zatovsky,Il'ya A. Gural'skiy,Ziyu Wei,Quanjun Li,Bingbing Liu,Y.A. Batman,A. V. Pashchenko,Georgiy Levchenko +11 more
TL;DR: In this paper , the magnetocaloric effect (MCE) of La 0.9Mn 1.1O3 (LMO) ceramics has been studied for the overall water splitting (OER) process.
References
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