Thermochromic properties of manganese oxides La1−xAxMnO3 (A=Ca, Ba)

Tang, Genchu; Yu, Yun; Chen, Wei; Cao, Yunzhen

doi:10.1016/j.matlet.2008.01.074

Cited by 29 publications

(11 citation statements)

References 19 publications

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“…For example, the emissivity for x = 0.1 varies from 0.48 at 243 K to 0.69 at 343 K and has a sudden change in the vicinity of the transition temperature. The results were similar to those reported by Shimazaki et al [11] and Tang et al [7]. All of these studies show that the sudden change of emissivity in the vicinity of the transition temperature is attributed to metal-insulator transition properties on the basis of the double-exchange effect.…”

Section: Normal Emissivity Of Samplessupporting

confidence: 92%

Emissivity and Optical Properties of Thermochromic Material La0.7Ca0.3−x Sr x MnO3 (0 ≤ x ≤ 0.3)

Fan

Xuan

2011

Int J Thermophys

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La 0.7 Ca 0.3−x Sr x MnO 3 (0 ≤ x ≤ 0.3) (LCSMO) is a thermochromic material. The material can show a phase transition from ferromagnetic-metal to paramagnetic-insulator under the appropriate doping level (x). In this paper, LCSMO compounds were synthesized by a conventional solid-state reaction method. The normal emissivity and the spectral reflectance of LCSMO with different doping levels (x) are experimentally investigated. Based on the spectral reflectance data, the optical constants (refractive index n and extinction coefficient k) are calculated by using Kramers-Kronig (K-K) relations. Then, the emissivity changing mechanism is discussed. The experimental results show that the emissivity of LCSMO increases with increasing temperature. For the samples with x = 0.1 and 0.15, their emissivity has a sudden change in the vicinity of the phase transition temperature T p .

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Section: Normal Emissivity Of Samplessupporting

confidence: 92%

Emissivity and Optical Properties of Thermochromic Material La0.7Ca0.3−x Sr x MnO3 (0 ≤ x ≤ 0.3)

Fan

Xuan

2011

Int J Thermophys

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“…The metal-insulator transition temperature (T MI ) reported for LCMO is to less than 293 K, from 160 K for x = 0.1 to 275 K for x = 0.5 [22], hence, the LCMO samples are in insulator-like state in the temperature range 293-373 K and no phase transition occurs in the whole temperature range. The result is also contradictory to Tang's report that LCMO increases with increasing temperature [18]. The differences would probably be due to relatively different surface conditions.…”

Section: Methodscontrasting

confidence: 99%

“…In general, emissivity of metal is low, while that of insulator is high. Thus, due to MI phase transition properties, infrared emissivity changes significantly with temperature for appropriate doped manganese oxides, which make them attractive as thermal control material [15][16][17][18]. According to Kirchhoff law, emissivity relates to waveband and temperature.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of infrared emissivity of doped manganese oxides in different wavebands (3–5 and 8–14μm)

Shen¹,

Xu²,

Shao³

et al. 2009

Journal of Alloys and Compounds

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“…Because of these ionic radii differences, concentration is very important to the crystal structure of the resulting compound. [10][11][12] The ionic radius of the Mn 4+ ion is smaller than that of Mn 3+ . Distortion of the perovskite structure characterized by tilting of the MnO 6 octahedra occurs as a result of doping, with the tilting angle dependent on concentration.…”

Section: Introductionmentioning

confidence: 99%

Structural, Electrical, and Magnetic Properties of High-Temperature-Sintered La1−x Na x MnO3 (0.05 ≤ x ≤ 0.35) Compounds

Irmak

Taşarkuyu

Coşkun

et al. 2014

Journal of Elec Materi

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The structural, electric, and magnetic properties of La 1Àx Na x MnO 3 (0.05 £ x £ 0.35) compounds have been investigated. The compounds were prepared by a standard sol-gel method then sintered at 1400°C for 24 h. The crystal structures were orthorhombic (Pbnm) for all Na concentrations, and the unit cell volumes, determined from the x-ray diffraction data, tended to decrease with increasing Na content. The high-temperature-sintering process resulted in a grainy structure with grain sizes of 5-30 lm. The Curie temperature (T C ) increased with increasing Na concentration up to x = 0.20, then decreased with further increase in Na concentration. The maximum magnetic entropy change (ÀDS M ) under a field change of 1.6 T was calculated to be $3 J/kg K for the sample containing 15% Na.

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Thermochromic properties of manganese oxides La1−xAxMnO3 (A=Ca, Ba)

Cited by 29 publications

References 19 publications

Emissivity and Optical Properties of Thermochromic Material La0.7Ca0.3−x Sr x MnO3 (0 ≤ x ≤ 0.3)

Emissivity and Optical Properties of Thermochromic Material La0.7Ca0.3−x Sr x MnO3 (0 ≤ x ≤ 0.3)

Temperature dependence of infrared emissivity of doped manganese oxides in different wavebands (3–5 and 8–14μm)

Structural, Electrical, and Magnetic Properties of High-Temperature-Sintered La1−x Na x MnO3 (0.05 ≤ x ≤ 0.35) Compounds

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