Electron doped (Sm1−x,Cax)MnO3 perovskite manganite as potential infrared thermochromic switch

Abstract

We have synthesized (Sm1−x,Cax)MnO3 and related compositions to show their potential use as thermochromic switch in the infrared range. Depending on temperature or composition, the single phase is stabilized using the polyacrilamide gel process. Infrared transmittance was measured on selected samples in the 1,42–25μm range. Relative contrast up to 0.773 is measured in the 8–14μm range. Full opacity in the 8–14μm range occurs at temperatures between 273 and 300K, depending on the composition. The potential application of perovskites manganites as thermochromic infrared switch or coating is discussed.

Effect of the sintering temperature on the properties of nanocrystalline Ca1−xSmxMnO3 (0≤x≤0.4) powders

“…4 and Tables 1 and 2). Our data is in agreement with the reported behaviour for the lattice parameters variation with the x value in the Ca 1−x Sm x MnO 3 series (0 ≤ x ≤ 0.4) [14][15][16][24][25][26][27]30]. The calculated lattice parameters values for the CaMnO 3 phase also agree well with the data reported in the literature [24][25][26][27]30].…”

“…The calculated lattice parameters values for the CaMnO 3 phase also agree well with the data reported in the literature [24][25][26][27]30]. In what concerns substituted samples, our data are in agreement with the ones reported earlier for the same phases prepared by high temperature ceramic route (near 1573-1873 K) [14][15][16]. However, it is important to point out that the heat treatments used in this work are distinct from the published ones.…”

“…As the calcination temperature is increased up to 1073, the samples crystallinity improves and a better definition of the XRD peak shape is observed. This effect is further enhanced with the heat treatment at 1473 K. The temperature of 873 K is much lower than those that have been reported for the formation of the perovskite phase employing the traditional ceramic method [13][14][15][16][17][18]. Fig.…”

“…Doping with electrons introduces mobile electrons into the e g band and consequently the interaction of these carriers via t 2g spins induces changes in the electrical and magnetic properties. The electron-doped manganites Ca 1−x Sm x MnO 3 have been recently investigated [13][14][15][16][17][18] by electrical resistivity, thermoelectric power, magnetic susceptibility, thermal conductivity, X-ray, neutron and electron diffractions homogeneity, particle size and morphology of the oxide materials. Therefore, the challenge of improving the preparation method and controlling the grain size still remains.…”

Infrared emissivities and microwave absorption properties of perovskite Sm0.5Sr0.5Co1−xFexO3 (0≤x≤0.5)

“…ordering or metal-insulator transitions, tunable around room temperatures [24,25]. LaMnO 3 systems doped by Sr at site A and Fe or Co, Ni at site B exhibit good microwave absorbing properties due to their special electromagnetism characteristic, especially colossal magnetoresistance effect.…”