Record details

Title
    Space weathering simulations through controlled growth of iron nanoparticles on olivine
Author
    Bradley, T.
    Britt, D.
    Čuda, J.
    Filip, J.
    Kašlík, J.
    Kletetschka, Günther
    Kohout, Tomáš
    Malina, O.
    Skála, Roman
    Šišková, K.
    Tuček, J.
    Zbořil, R.
Language
    anglicky
Publication type
    článek v odborném periodiku
Source title - serial
    Icarus
Vol./nr.
    Roč. 237, 15 July
Pages
    s. 75-83
Year
    2014
Notes
    Projekt: LH12079, GA MŠk3cav_un_auth*0281796
    Rozsah: 9 s. : P
Subject category
    asteroids, surface
    Moon, surface
    regoliths
    spectroscopy
Keyword
    Controlled
    Growth
    Iron
    Nanoparticles
    Olivine
    Simulations
    Space
    Through
    Weathering
Abstract (in english)
   Airless planetary bodies are directly exposed to space weathering. The main spectral effects of space weathering are darkening, reduction in intensity of silicate mineral absorption bands, and an increase in the spectral slope towards longer wavelengths (reddening). Production of nanophase metallic iron (npFe0) during space weathering plays major role in these spectral changes. A laboratory procedure for the controlled production of npFe0 in silicate mineral powders has been developed. The method is based on a two-step thermal treatment of low-iron olivine, first in ambient air and then in hydrogen atmosphere. Through this process, a series of olivine powder samples was prepared with varying amounts of npFe0 in the 7-20nm size range. A logarithmic trend is observed between amount of npFe0 and darkening, reduction of 1μm olivine absorption band, reddening, and 1μm band width.
   Olivine with a population of physically larger npFe0 particles follows spectral trends similar to other samples, except for the reddening trend. This is interpreted as the larger, ~40-50nm sized, npFe0 particles do not contribute to the spectral slope change as efficiently as the smaller npFe0 fraction. A linear trend is observed between the amount of npFe0 and 1μm band center position, most likely caused by Fe2+ disassociation from olivine structure into npFe0 particles.
Contributor
    AV ČR Brno, Geologický ústav
Contributor code
    AV ČR, GLÚ
Source format
    U
Import date
    23. 10. 2014