Temperature dependence of total hemispherical emittance in perovskite-type manganese oxides, La1–xSrxMnO3
Kazunori Shimazaki, Sumitaka Tachikawa, Akira Ohnishi, Yuji Nagasaka
La1-xSrxMnO3 is a manganese oxide with a perovskite-type structure, LaMnO3, by substitution of La3+ sites with Sr2+, which shows a variety of phenomena with changing hole concentration (x). The total hemispherical emittance, εH, of La1-xSrxMnO3 (x = 0, 0.175, and 0.3) in the vicinity of the metal – insulator transition temperature was measured by the calorimetric method in the temperature range 173 – 373 K. Remarkable differences in εH resulted with changing hole concentration (x). It was observed that εH of La0.825Sr0.175MnO3 changed notably at about 280 K accompanied by the metal – insulator transition and the maximum amount of variation in εH was 0.42. The effects of surface conditions and thicknesses of samples were also observed. The uncertainty in the measurement of εH was estimated to be at most ±2.2% from 173.15 to 373.15 K.