Unusual ferromagnetism enhancement in ferromagnetically optimal manganite La0.7−yCa0.3+yMn1−yRuyO3 (0≤y<0.3): the role of Mn-Ru t2g super-exchange

Abstract

The eg-orbital double-exchange mechanism as the core of physics of colossal magnetoresistance (CMR) manganites is well known, which usually covers up the role of super-exchange at the t2g-orbitals. The role of the double-exchange mechanism is maximized in La0.7Ca0.3MnO3, leading to the concurrent metal-insulator transition and ferromagnetic transition as well as CMR effect. In this work, by a set of synchronous Ru-substitution and Ca-substitution experiments on La0.7–yCa0.3+yMn1–yRuyO3, we demonstrate that the optimal ferromagnetism in La0.7Ca0.3MnO3 can be further enhanced. It is also found that the metal-insulator transition and magnetic transition can be separately modulated. By well-designed experimental schemes with which the Mn3+-Mn4+ double-exchange is damaged as weakly as possible, it is revealed that this ferromagnetism enhancement is attributed to the Mn-Ru t2g ferromagnetic super-exchange. The present work allows a platform on which the electro-transport and magnetism of rare-earth manganites can be controlled by means of the t2g-orbital physics of strongly correlated transition metal oxides.

Dye-Cucurbit[n]uril Complexes as Sensor Elements for Reliable Pattern Recognition of Biogenic Polyamines

“…5c,15 Spermine and spermidine, which differ by one propyl amine moiety, are also distinguished by H@CB [7] as shown by 2.4-fold smaller F value response to spermine in fluorescence output (the F values for spermidine and spermine are 0.64 and 0.27, respectively, in Table S2) showing that spermine is a stronger binder to CB [7] by providing an additional amine to interact with carbonyl on the portal of CB [7]. 16 ( Figure 3a). Unlike H@CB [7], H@CB[8] did not provide a drastic difference in magnitude of fluorescence responses among the aliphatic amines (Figure 3a).…”

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“…Хотя на-личие многоатомных вакансий имеет фундаментальное значение для понимания формирования и функциони-рования слоистых материалов, механизм их зарождения не полностью раскрыт. Эта проблема решалась методом расчетов по теории функционала плотности с упором на изучение реконструкции, слипания и диффузии ваканси-онных дефектов в свободно стоящем силицене [16]. Была исследована адсорбция и диффузия атомов кремния в пределах силиценовых слоев, приводящая к открытию значительной части запрещенной зоны в силицене.…”

Flexible Asymmetric Supercapacitors Based on Nitrogen‐Doped Graphene Hydrogels with Embedded Nickel Hydroxide Nanoplates

“…[31] Other encouraging results have been achieved; [32,33] however, little work has been focused on the combination of N-doped graphene (NG) hydrogels with Ni(OH) 2 of specific shapes. The 3 D porous framework structure is very stable, and its large available surface allows the uniform distribution of the secondary nanostructures with specific shapes, [34] which is promising for the integration of the high conductivity and large accessible area of the material.…”