Thermal Emittance of $$\hbox {La}_{0.7}\hbox {Ca}_{0.3-x}\hbox {K}_x\hbox {MnO}_3$$ La 0.7 Ca 0.3 -

Switchable and Tunable Radiative Cooling: Mechanisms, Applications, and Perspectives

“…Dual-mode bimorph structures rely on stress changes in an additional temperature-responsive layer to achieve automatic switching between radiative cooling in high-temperature environments and solar heating in low-temperature environments. , Though the complicated design may not be conducive to large-scale production, the bimorph structure enriches the functionality of temperature-adaptive STRCs with excellent thermoregulation performance. On the other hand, PCMs (including VO 2 , GST, − and perovskites , ) are more widely used in temperature-adaptive STRCs for their temperature-sensitive optical properties in the IR range. For example, VO 2 undergoes temperature-driven and reversible metal–insulator phase change upon heating across its transition temperature with a drastic contrast in IR refractive index .…”

Investigation of thermal control in phase-changing ABO3 perovskites via first-principles predictions: general mechanism of emittance

“…14 Another material, Ge 2 Sb 2 Te 5 , has been found to exhibit extraordinarily low (near zero) emission below 1073 K and a high emissivity of B1.0 above 1073 K. 15 Both pure (La,Sr)MnO 3 and doped (La,Sr)MnO 3 have also been examined experimentally. [16][17][18] The maximum emittance variation of bulk La 0.825 Sr 0.175 MnO 3 was found to be 0.546 in the 1.25-25 mm waveband at temperatures of 173-373 K. 19 The La 0.7 Ca 0.12 Sr 0.18 MnO 3 /ALO/Ag/mica structure was found to exhibit a remarkably tunable emissivity, and its emittance variation was found to be 0.53 and 0.63 in the wavelength ranges 3-5 mm and 8-14 mm, respectively, at temperatures of 173-373 K. 20 In comparison, the emittance variations of an La 0.8 Sr 0.2 MnO 3 coating were found to be only 0.041 and 0.007 under the same conditions. 21 Meanwhile, there have been several different proposed explanations for the coupling relationship between phase changes and emittance.…”

Investigation of thermal control in phase-changing ABO3 perovskites via first-principles predictions: general mechanism of solar absorptivity

“…Meanwhile, the large solar absorbance (B0.8) of LSMO and doped LSMO has also limited their application in the field of intelligent thermal control. [23][24][25][26][27] Thus, investigating the more universal mechanisms of solar absorbance during phase changes is very challenging. Resolving the following issues is required for enabling intelligent, thermally controlled materials: (i) understanding how the crystal structures, electrons, and magnetism of these phasechanging materials affect the solar absorbance during the phasechanging processes in general materials; and (ii) determining what atomistic and crystalline characteristic perovskite has a tunable solar absorptivity.…”