Effect of Mg addition on LaMnO3 ceramic system

Supelano, G. I.; Barón-González, A. J.; Santos, Armando Sarmiento; Ortíz, César; Gómez, Julieth Alexandra Mejía; Vargas, Carlos Arturo Parra

doi:10.1016/j.jmrt.2017.05.012

Cited by 16 publications

(7 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In recent decades, a wide range of researches have been conducted on manganese oxide compounds with perovskite structure called manganite with chemical formula of REMnO 3 (RE: trivalent rare-earth ion like La, Pr, Sm & Nd). This structure is an antiferromagnetic insulator [1] and what makes it considerable is the mixed valence manganites with general structure of RE 1−x AE x MnO 3 (AE: divalent alkaline-earth ion like Sr, Ca, Ba, etc.) which is practical in many different fields of industrial technology [2].…”

Section: Introductionmentioning

confidence: 99%

Magnetoresistance temperature dependence of LSMO and LBMO perovskite manganites

2018

View full text Add to dashboard Cite

La 0.7 Sr 0.3 MnO 3 (LSMO) and La 0. 7 Ba 0.3 MnO 3 (LBMO) Polycrystalline manganite nanoparticles were prepared by combustion method using glycine fuel. The ignition process was done at 360 °C and 330 °C for LSMO and LBMO, respectively. Both of the samples have rhombohedral structure using XRD analysis. The reduction is observed in electrical resistivity when external magnetic field is applied during the decrease in temperature from 300 to 89 °K, which is due to the tunneling between particles. The magnetoresistance (MR) of samples was measured in this range of temperature in both the presence and absence of a magnetic field of about 10 kG. The colossal role of a kind of extrinsic MR which is 19% and 22% for LSMO and LBMO, respectively, has been investigated in this research. The metal-insulator transition temperature of 200 °K is recorded for LBMO.

show abstract

Section: Introductionmentioning

confidence: 99%

Magnetoresistance temperature dependence of LSMO and LBMO perovskite manganites

2018

View full text Add to dashboard Cite

show abstract

“…Durante o aquecimento, observa-se o Mn variando de Mn4+ para Mn3+ e, no resfriamento, ocorre a reação inversa. A elevada atividade de catalisadores do tipo LaMnO 3 é atribuída a presença do manganês nestes dois estados de oxidação distintos, resultando num constante excesso de oxigênio na estrutura [12].…”

Section: Figura 6: Perfis De Tpsr Dos Catalisadoresunclassified

“…Os sítios A e B podem ser substituídos pordiversos elementos, possibilitando a formação de perovskitas de fórmulas bastante variadas [11]. A atividade é mais influenciada pela natureza do sítio B, enquanto o sítio A tem ação majoritária na estabilidade do catalisador [12].…”

unclassified

Síntese e caracterização de perovskitas LaMnO3 e γ-alumina como catalisadores para a reação de combustão do metano

Santos¹,

Santos²,

Resini

et al. 2018

Matéria (Rio J.)

View full text Add to dashboard Cite

RESUMO Catalisadores do tipo perovskita, LaMnO3, foram sintetizados pelos métodos citrato e coprecipitação. Parte destes materiais foi suportado em γ-alumina ou impregnados por via úmida com Pd e/ou Sn na concentração de 1% em massa. Os catalisadores foram avaliados na reação de combustão total do metano, tendo a sua atividade medida através de reação superficial termoprogramada (TPSR). Para tanto, as amostras foram aquecidas até 800°C, a uma taxa de 10°C/min, sob um fluxo de 50 mL/min de uma mistura contendo CH4, O2 e N2 com concentrações molares de 4%, 1% e 95%, e He (50mL/min). Como padrão de comparação, sintetizou-se também uma amostra de referência de PdO/γ-Al2O3. As amostras foram caracterizadas por análise termogravimétrica (ATG), difração de raios X (DRX) e tiveram a sua área superficial medida por BET. As amostras contendo paládio foram ainda analisadas na reação de oxidação a temperatura programada (TPO) de modo a determinar a estabilidade das fases PdO presentes nestes materiais. Todas as amostras se apresentaram ativas para a reação de combustão do metano, sendo os materiais oriundos da rota citrato superiores aos materiais coprecipitados. A adição de paládio, mesmo em baixa concentração, mostrou-se positiva para a atividade catalítica, ao contrário do estanho, que resultou numa redução na conversão final de metano para estes materiais.

show abstract

“…More recently, these studies were extended to other lanthanide‐based compounds . However, a more recent study on La (1‐ x ) Mg x MnO 3 ( x = 0.10, 0.25, and 0.50) reported for a rhombohedral

R \bar{3} c

symmetry and a semiconducting behavior …”

Section: Introductionmentioning

confidence: 99%

Elaboration and Characterization of Materials from the LaMnO₃–BiMnO₃ Binary System

Djahmoum¹,

Kechai²,

Marchet

2020

Physica Status Solidi (a)

View full text Add to dashboard Cite

The study of the La(1‐x)BixMnO3 system is conducted using X‐ray diffraction (XRD) and electrical measurements. A continuous solid solution is evidenced for the LaMnO3 rich part of this system (x ≤ 0.6). According to the analyses of XRD results, a rhombohedral symmetry (R3¯c) is observed for x ≤ 0.4 and a cubic structure for x = 0.5. The structural study allows to determine an increase in the mean perovskite lattice parameter, together with a decrease in the rhombohedral angle up to a cubic symmetry for x = 0.5. For x > 0.6, the system is no more single‐phased. Impedance measurements are conducted for ceramics in a wide‐frequency range (100 Hz–1 MHz), between room temperature and 800 °C. The exponential decrease in the alternative current (AC) conductivities (σAC) and the room temperature values correspond to a semiconducting behavior. Direct current (DC) conductivity measurements (σDC) are also performed below room temperature (25 K < T < 300 K). The results evidence for a metal–insulator phase transition. For the exponential part of the σDC curves, the gap energy is between 0.1 and 0.2 eV, confirming the semiconductor behavior of these materials.

show abstract

Effect of Mg addition on LaMnO3 ceramic system

Cited by 16 publications

References 9 publications

Magnetoresistance temperature dependence of LSMO and LBMO perovskite manganites

Magnetoresistance temperature dependence of LSMO and LBMO perovskite manganites

Síntese e caracterização de perovskitas LaMnO3 e γ-alumina como catalisadores para a reação de combustão do metano

Elaboration and Characterization of Materials from the LaMnO₃–BiMnO₃ Binary System

Contact Info

Product

Resources

About

Effect of Mg addition on LaMnO3 ceramic system

Cited by 16 publications

References 9 publications

Magnetoresistance temperature dependence of LSMO and LBMO perovskite manganites

Magnetoresistance temperature dependence of LSMO and LBMO perovskite manganites

Síntese e caracterização de perovskitas LaMnO3 e γ-alumina como catalisadores para a reação de combustão do metano

Elaboration and Characterization of Materials from the LaMnO3–BiMnO3 Binary System

Contact Info

Product

Resources

About

Elaboration and Characterization of Materials from the LaMnO₃–BiMnO₃ Binary System