@article{fdi:010061872,
  title = {{I}nfrared spectroscopic properties of goethite : anharmonic broadening, long-range electrostatic effects and {A}l substitution},
  author = {{B}lanchard, {M}. and {B}alan, {E}tienne and {G}iura, {P}. and {B}eneut, {K}. and {Y}i, {H}. {H}. and {M}orin, {G}. and {P}inilla, {C}. and {L}azzeri, {M}. and {F}loris, {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he infrared spectrum and its temperature dependence (20-320 {K}) were collected on a synthetic goethite sample (alpha-{F}e{OOH}). {I}n addition, the infrared powder absorption spectrum of goethite and aluminum-substituted goethite was computed using ab initio quantum mechanical calculations based on density functional theory. {T}his combined experimental and theoretical approach allows (1) the unequivocal assignment of absorption bands to the corresponding vibrational modes, (2) separate identification of the effects of the particle shape and of the aluminum substitution on the infrared spectrum, and (3) a discussion of the anharmonic properties and the origin of the line broadening in goethite. {I}n particular, the two well-resolved {OH} bending absorption bands show different temperature evolution. {T}heir detailed analysis suggests that the broadening of the band at similar to 800 cm(-1) cannot be described solely by a usual three-phonon process. {T}he strong anharmonic behavior of this mode implies the addition of a four-phonon process, such as a pure dephasing process. {I}n our calculations, the effect of the {H}ubbard {U} correction is also investigated and found to be most visible on the {OH} stretching and bending modes, in relation to the associated structural relaxation. {T}he {OH} stretching frequencies decrease, leading to a better agreement with experimental frequencies, while the {OH} bending frequencies increase.},
  keywords = {{G}oethite ; {A}luminum substitution ; {D}ensity functional theory ; {I}nfrared spectroscopy},
  booktitle = {},
  journal = {{P}hysics and {C}hemistry of {M}inerals},
  volume = {41},
  numero = {4},
  pages = {289--302},
  ISSN = {0342-1791},
  year = {2014},
  DOI = {10.1007/s00269-013-0648-7},
  URL = {https://www.documentation.ird.fr/hor/fdi:010061872},
}