Aggregation-based crystal growth and microstructure development in natural iron oxyhydroxide biomineralization products.
Crystals are generally considered to grow by attachment of ions to inorganic surfaces or organic templates. High-resolution transmission electron microscopy of biomineralization products of iron-oxidizing bacteria revealed an alternative coarsening mechanism in which adjacent 2- to 3-nanometer particles aggregate and rotate so their structures adopt parallel orientations in three dimensions. Crystal growth is accomplished by eliminating water molecules at interfaces and forming iron-oxygen bonds. Self-assembly occurs at multiple sites, leading to a coarser, polycrystalline material. Point defects (from surface-adsorbed impurities), dislocations, and slabs of structurally distinct material are created as a consequence of this growth mechanism and can dramatically impact subsequent reactivity.
Banfield
J F
JF
Department of Geology and Geophysics, University of Wisconsin-Madison, Madison, WI 53706, USA. jill@geology.wisc.edu
Welch
S A
SA
Zhang
H
H
Ebert
T T
TT
Penn
R L
RL
D020562:Betaproteobacteria / Q000378:metabolism*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003102:Colloids; D003460:Crystallization; D005290:Ferric Compounds; D005293:Ferritins / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry*; D058085:Iron Compounds / Q000737:chemistry*; D008854:Microscopy, Electron; D008903:Minerals / Q000737:chemistry*; D010084:Oxidation-Reduction
D003102:Colloids; D005290:Ferric Compounds; D006878:Hydroxides; D058085:Iron Compounds; D008903:Minerals; C094886:goethite; C092844:ferric oxyhydroxide; D005293:Ferritins