Publication
Names
  • Yinsheng Wang
  • Atsushi Muramatsu
  • Tadao Sugimoto
Title
FTIR analysis of well-defined α-Fe2O3 particles
Abstract
The FTIR spectra of well-defined hematite (alpha-Fe203) particles varying in size, shape and internal structure have systematically been analyzed. It has been found that the absorption peak frequencies of the pseudocubic particles are located between the corresponding theoretical peak frequencies of spheres and cubes and shift to lower frequencies as particle size increases, corresponding approximately with the Mie theory. However, the basic spectrum pattern was determined by the morphology of the particles. The observation of ellipsoids with various aspect ratios revealed some essential discrepancies in the peak frequency between experiment and the theory on the surface phonon modes in small particles, even if the particles were completely dispersed in the medium. The internal structure mainly affects the peak width, which increases with the decreasing subcrystal size. Finally, the effects of aggregation on the IR spectrum are discussed.
Keywords
Hematite, Infrared spectrum, Internal structure, Size, Shape
Content
spectral data
Year
1998
Journal
Colloids and Surfaces A: Physicochemical and Engineering Aspects
Volume
134
Number
3
Pages
281 - 297
Document type
article
Publication state
published