Temperature Dependences of IR Spectral Band Frequencies of Soils

Abstract

Temperature dependences of the IR spectra of different size aggregate fractions of chernozem and soddy podzol soils in the range 25-215 °C (298-488 K with a step of 2.5 °C by heating in the air) for different agriculture use samples were investigated. The band maximum temperature dependence can be much more stable to experimental conditions and thus serve as a new quantitative parameter characterizing soils with IR spectroscopy. For the first time, a reversible change in the frequencies of the band maxima in IR spectra upon heating was observed, which can be interpreted as forming structures with a particular order in the dry state. The difference in the behavior of the lattice vibrations of quartz, hydrogen bonds, and organic matter that can be used to differentiate soils was found and discussed.