Neutron diffraction study of the size-induced tetragonal to monoclinic phase transition in zirconia nanocrystals.
Accurate neutron powder diffraction experiments at several temperatures allow one to monitor the reconstructive tetragonal to monoclinic phase transition as a function of the size of zirconia nanoparticles. The structure of the tetragonal phase observed in the nanocrystals is identical to that observed in micrometric zirconia above 1400 K. A uniaxial strain depending on grain size is observed. The phase transition occurs above a threshold crystal size. These results are analyzed within the Landau theory and can be understood as a mechanism of size-dependent phase transition where the primary order parameter is altered by the nanoparticle size.
Baldinozzi
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Laboratoire de Structures, Propriétés et Modélisation des Solides, UMR CNRS 8580 Ecole Centrale Paris, F-92295 Châtenay Malabry, France.
Simeone
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Gosset
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Dutheil
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