Journal ArticleDOI
Effect of hyperstoichiometric manganese on the structure and transport, magnetic, and magnetoresistance properties of manganite-lanthanum (La 0.7 Ca 0.3 ) 1 − x Mn 1 + x O 3 perovskites
V. P. Pashchenko,A. V. Pashchenko,V. K. Prokopenko,Yu. F. Revenko,A. A. Shemyakov,A. G. Sil’cheva +5 more
TLDR
In this paper, X-ray diffraction, resistive, magnetic, 55Mn NMR, and magnetoresistance methods were used to study the perovskite structure and its average ionic radius.Abstract:
Ceramic (La0.7Ca0.3)1 − x
Mn1 + x
O3 samples are studied by X-ray diffraction, resistive, magnetic, 55Mn NMR, and magnetoresistance methods. The concentration changes of lattice parameter a of the cubic perovskite structure and its average ionic radius are in good agreement if the concentrations of anion and cation vacancies and nanostructured clusters with Mn2+ in the A positions increase with x. Phase transition temperatures T
ms
and T
c
weakly depend on x, and the electrical resistivity and the activation energy decrease substantially with increasing x due to a change in the imperfection of the perovskite structure. An analysis of the broad asymmetric 55Mn NMR spectra of the samples indicate a high-frequency Mn3+↔ Mn4+ electron superexchange and nonuniform magnetic and valence states of these ions because of a nonuniform distribution of ions and defects, which decrease the amplitude resonance frequency with increasing x. The magnetoresistive (MR) effect near phase-transition temperatures T
ms
and T
c
increases substantially with x and is caused by the effect of a magnetic field on the scattering of charge carriers by intracrystallite nanostructured heterogeneities of an imperfect perovskite structure. The second MR effect is located in the low-temperature range, is related to tunneling through mesostructural crystallite boundaries, and decreases weakly with increasing x. A correlation is found between the hyperstoichiometric manganese content, the imperfection of the perovskite structure, and the magnitude of the MR effect.read more
Citations
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Critical phenomena of magnetization, magnetocaloric effect, and superparamagnetism in nanoparticles of non-stoichiometric manganite
N.A. Liedienov,V. M. Kalita,A. V. Pashchenko,Yu. I. Dzhezherya,I.V. Fesych,Quanjun Li,Georgiy Levchenko +6 more
TL;DR: In this article, the properties of the La0.6Ag0.2Mn1.2O3 manganite with superstoichiometric manganese have been determined using nitrate pyrolysis method.
Journal ArticleDOI
Modification of multifunctional properties of the magnetoresistive La0.6Sr0.15Bi0.15Mn1.1-xBxO3-δ ceramics when replacing manganese with 3d-ions of Cr, Fe, Co, Ni
A. V. Pashchenko,N.A. Liedienov,V. P. Pashchenko,V. K. Prokopenko,V.V. Burhovetskii,A.V. Voznyak,I.V. Fesych,D.D. Tatarchuk,Y.V. Didenko,A.I. Gudymenko,V. P. Kladko,Abdulkarim Amirov,Georgiy Levchenko +12 more
TL;DR: In this article, the influence of manganese substitution with 3d-ions on the structure, defectiveness, microstructure as well as resistive, dielectric and magnetoresistive properties of single-phase nonstoichiometric La0.6Sr0.15Mn1.1-xBxO3-δ (B = Cr, Fe, Co, Ni) compositions have been studied.
Journal ArticleDOI
Smart magnetic nanopowder based on the manganite perovskite for local hyperthermia
A. V. Pashchenko,A. V. Pashchenko,N.A. Liedienov,I.V. Fesych,Quanjun Li,V. G. Pitsyuga,V.A. Turchenko,V. G. Pogrebnyak,Bingbing Liu,Georgiy Levchenko +9 more
TL;DR: In this article, a manganite perovskite with super-stoichiometric manganese has been synthesized, which consists of soft spherical-like ferromagnetic nanoparticles with an average size of 65 nm and with a narrow temperature range of the magnetic phase transition at 42 °C.
Journal ArticleDOI
The role of structural and magnetic inhomogeneities in the formation of magneto-transport properties of the La0.6−xSmxSr0.3Mn1.1O3−δ ceramics
А.V. Pashchenko,V. P. Pashchenko,V. K. Prokopenko,Yu. F. Revenko,А.S. Мazur,V. V. Burchovetskii,V.А. Тurchenko,N.A. Liedienov,V. G. Pitsyuga,Georgiy Levchenko,V. P. Dyakonov,H. Szymczak +11 more
TL;DR: In this article, the role of structural and magnetic inhomogeneities in the formation of magneto-transport properties of the La 0.6−xSmxSr0.3Mn1.1O3−δ (x=0-0.6) ceramics was investigated.
Journal ArticleDOI
Structure defects, phase transitions, magnetic resonance and magneto-transport properties of La0.6–xEuxSr0.3Mn1.1O3–δ ceramics
N.A. Liedienov,A. V. Pashchenko,V. P. Pashchenko,V. K. Prokopenko,Yu. F. Revenko,Anton S. Mazur,V. Ya. Sycheva,V. I. Kamenev,Georgiy Levchenko +8 more
TL;DR: In this article, the defects, magnetic resonance and magneto-transport properties of La0.6-xEuxSr0.3Mn1.1O3-δ magnetoresistive ceramics were investigated by x-ray diffraction, thermogravimetric, resistance, magnetic, 55Mn NMR and magnetoresistance methods.
References
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