Electron transport behavior and charge ordering phenomena in La0.5Ca0.5MnO3

Kekade, Shankar S.; Devan, Rupesh S.; Deshmukh, Alka V.; Phase, D. M.; Choudhary, R. J.; Patil, S. F.

doi:10.1016/j.jallcom.2016.05.003

Cited by 16 publications

(5 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mn 2p 3/2 and Mn 2p 1/2 have energy separations of 11.45, 11.62, and 11.78 eV for LCM, LCA10, and LCA20, respectively, whereas Mn typically has an energy separation of 11.05 eV in its metallic state . A greater energy separation value indicates the existence of Mn in its oxidative state . Furthermore, the BE difference between Mn 2p 3/2 and O 1s spectra (Δ E Mn 2p 3/2 –O 1s ) may be used to indicate the evolution of Mn 4+ species over Mn 3+ .…”

Section: Resultsmentioning

confidence: 99%

“…53 A greater energy separation value indicates the existence of Mn in its oxidative state. 54 Furthermore, the BE difference between Mn 2p 3/2 and O 1s spectra (ΔE Mn 2pd 3/2 −O 1s ) may be used to indicate the evolution of Mn 4+ species over Mn 3+ . The (ΔE Mn 2pd 3/2 −O 1s ) value for LCM, LCA10, and LCA20, respectively, is found to be 112.2, 112.35, and 112.5 eV, implying the presence of a Mn 4+ oxidative state in the studied specimens.…”

Section: The Journal Of Physical Chemistry Cmentioning

confidence: 99%

See 1 more Smart Citation

Multifaceted Roles of Ag⁺ Ions within and outside La–Ca–MnO₃ Perovskite Manganites: Unveiling the Room Temperature Magnetocaloric Effect

Nadig,

Toulemonde,

Alagarsamy

et al. 2024

J. Phys. Chem. C

View full text Add to dashboard Cite

The primary objective of this study is to unravel the role of Ag + ions in A-site substitutions and to explore their potential in achieving room-temperature magnetocaloric response. The investigation is structured around three distinct scenarios: direct Ag + substitution, Ag + introduction as a composite, and the absence of Ag + as an A-site deficient system. Through these approaches, the study seeks to elucidate the multifaceted roles played by Ag + ions, providing valuable insights into their influence on structural and magnetic properties. In the case of Ag + substitution at the A-site, temperature-dependent magnetization reveals a two-step dependence with distinctive inflection points, attributed to the Curie points of the Pnma and R3̅ c phases, respectively. As a consequence, the maximum value of the isothermal magnetic entropy change (−ΔS M ) for the lower substitution (x = 0.05) is found to be 4.5 J/kg K, achieved at 273.5 K for ΔH = 20 kOe, while the same is retained at about 4.25 J/kg K for higher substitution (x = 0.2). Remarkably, −ΔS M peaks at room temperature of 306.5 K in case of x = 0.2. Furthermore, an effective screening is undertaken, evaluating the figure-of-merit to elucidate the suitability and efficacy of the material. The temperature-averaged entropy change (TEC) values, TEC (ΔT H−C = 3 K) and TEC (ΔT H−C = 5 K), reached 4.15 and 4.09 J/kg K, respectively, under a low magnetic field change of 20 kOe. Overall, the tuning of the phase transition without compromising the low-field magnetocaloric response was achieved solely through substitution, highlighting its pivotal role over composite and deficient systems.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: The Journal Of Physical Chemistry Cmentioning

confidence: 99%

Multifaceted Roles of Ag⁺ Ions within and outside La–Ca–MnO₃ Perovskite Manganites: Unveiling the Room Temperature Magnetocaloric Effect

Nadig,

Toulemonde,

Alagarsamy

et al. 2024

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…We apply a TE optimization procedure to the half-doped manganite Ca 0.5 L 0.5−x Bi x MnO 3 (x = 0, 0.25) (CLBMO). Ca 0.5 L 0.5 MnO 3 (CLMO) as a transition compound exhibits the interesting phenomenon of ferromagnetic (FM), paramagnetic (PM), antiferromagnetic (AFM), and charge order (CO) competition [27][28][29][30]. The AFM regularity refers to the long-range CO in which the electron charge is localized around the Mn 3+ /Mn 4+ ion [30,31].…”

Section: Introductionmentioning

confidence: 99%

Thermoelectric optimization using first principles calculation and single parabolic band model: a case of Ca_0.5La_0.5−xBi _x MnO₃ (x = 0, 0.25)

Raharjo,

Kurniawan,

Soegijono

et al. 2024

Modelling Simul. Mater. Sci. Eng.

View full text Add to dashboard Cite

Conducting optimization calculations for thermoelectric performance can be beneficial in guiding the direction of further experimental work. In our study, we utilize a combination of the first principle, Boltzmann transport and restructured single parabolic band model to investigate the half-doped semiconductors based on manganite. Ca0.5La0.5-xBixMnO3 (x = 0, 0.25) as samples shows the power factor (PF) optimum value of 30% and 69% for x = 0 and 0.25, respectively at a temperature of 800 K. In addition, both samples show two to three orders of magnitude smaller lattice thermal conductivity than their electronic thermal conductivity. This excludes complex phononic transport mechanisms from the calculation of the figure of merit (ZT). The ZT calculations of CLMO and CLBMO are corrected by the ratio of the transport relaxation time of electrical conductivity to the transport relaxation time of electronic thermal conductivity by the Lorenz number, resulting in ZT values of 0.063 and 0.327 at a temperature of 800 K, respectively.

show abstract

“…For example, La 1−x Sr x MnO 3 compounds are ferromagnetic metals for 0.1 < x < 0.5 and become antiferromagnetic metals for 0.5 < x < 0.9 [1][2][3][4][5][6][7][8]12,13,21]. The La 1−x Ca x MnO 3 compounds with 0.2 < x < 0.5 are also metallic ferromagnets but show charge ordered antiferromagnetism for 0.5 < x < 0.9 [22][23][24]. Thus, as a function of x, in the compositions La 1−x A x MnO 3 , the average valence of Mn ions is changed from 3+ (x = 0) to 4+ (x = 1) by replacing La 3+ ions in LaMnO 3 with A 2+ ions, and simultaneously, the intermediate compositions exhibit a competition between ferromagnetic and antiferromagnetic orderings.…”

Section: Introductionmentioning

confidence: 99%

“…However, surprisingly, the half-doped case with x = 0.5 shows some differences in their physical properties depending on the A ion, although they possess an average Mn valence of 3.5. Namely, La 0.5 Ca 0.5 MnO 3 is a ferromagnetic insulator which shows charge order [22][23][24], while La 0.5 Sr 0.5 MnO 3 is ferromagnetic and metallic [25,26]. The origin of this difference is the size mismatch between La 3+ and A 2+ , which randomly occupy the same crystallographic site [20].…”

Section: Introductionmentioning

confidence: 99%

Electronic structure of Tb0.5Sr0.5MnO3

et al. 2021

View full text Add to dashboard Cite

We study the electronic structure of single-crystal Tb 0.5 Sr 0.5 MnO 3 , a non-charge-ordered mixed-valent semiconductor which exhibits a glassy magnetic ground state. We use the techniques of soft x-ray photoemission, hard x-ray photoemission, x-ray absorption, and resonant photoemission spectroscopy to investigate the occupied and unoccupied electronic states of Tb 0.5 Sr 0.5 MnO 3 . Core level photoemission and x-ray absorption spectroscopy allow us to determine the valence states of Tb, Sr, and Mn ions in Tb 0.5 Sr 0.5 MnO 3 . Model charge transfer multiplet calculations of core level photoemission and x-ray absorption spectra are employed to separate out the Mn 3+ and Mn 4+ states and confirm their relative concentrations. Resonant photoemission spectroscopy across the Mn 2p-3d threshold shows clear resonant enhancement of the Mn 3d partial density of states and two-hole correlation satellites. A Cini-Sawatzky analysis gives on-site Coulomb energy U dd ∼ 5.5 ± 0.2 eV for the Mn 3d n states and U pd = 0.7 eV ± 0.2 eV for the Mn 3d n+1 L 1 states. The O 1s-2p resonant photoemission is used to identify the O 2p two-hole correlation satellite which provides U pp ∼ 3.4 ± 0.2 eV for the O 2p states. Valence band photoemission indicates a small-gap semiconductor (<100 meV) consistent with electrical transport measurements. The estimated electronic structure parameters of the on-site Coulomb energies, in combination with the charge transfer energy and the hybridization strength obtained from the model calculations, indicate that Tb 0.5 Sr 0.5 MnO 3 is a strongly correlated charge transfer type semiconductor.

show abstract

Electron transport behavior and charge ordering phenomena in La0.5Ca0.5MnO3

Cited by 16 publications

References 34 publications

Multifaceted Roles of Ag⁺ Ions within and outside La–Ca–MnO₃ Perovskite Manganites: Unveiling the Room Temperature Magnetocaloric Effect

Multifaceted Roles of Ag⁺ Ions within and outside La–Ca–MnO₃ Perovskite Manganites: Unveiling the Room Temperature Magnetocaloric Effect

Thermoelectric optimization using first principles calculation and single parabolic band model: a case of Ca_0.5La_0.5−xBi _x MnO₃ (x = 0, 0.25)

Electronic structure of Tb0.5Sr0.5MnO3

Contact Info

Product

Resources

About

Electron transport behavior and charge ordering phenomena in La0.5Ca0.5MnO3

Cited by 16 publications

References 34 publications

Multifaceted Roles of Ag+ Ions within and outside La–Ca–MnO3 Perovskite Manganites: Unveiling the Room Temperature Magnetocaloric Effect

Multifaceted Roles of Ag+ Ions within and outside La–Ca–MnO3 Perovskite Manganites: Unveiling the Room Temperature Magnetocaloric Effect

Thermoelectric optimization using first principles calculation and single parabolic band model: a case of Ca0.5La0.5−x Bi x MnO3 (x = 0, 0.25)

Electronic structure of Tb0.5Sr0.5MnO3

Contact Info

Product

Resources

About

Multifaceted Roles of Ag⁺ Ions within and outside La–Ca–MnO₃ Perovskite Manganites: Unveiling the Room Temperature Magnetocaloric Effect

Multifaceted Roles of Ag⁺ Ions within and outside La–Ca–MnO₃ Perovskite Manganites: Unveiling the Room Temperature Magnetocaloric Effect

Thermoelectric optimization using first principles calculation and single parabolic band model: a case of Ca_0.5La_0.5−xBi _x MnO₃ (x = 0, 0.25)