Effect of oxide additions on the polymorphism of tantalum pentoxide. III. ""Stabilization"" of the low temperature structure type
1970; The National Institute of Standards and Technology; Volume: 74A; Issue: 4 Linguagem: Inglês
10.6028/jres.074a.038
ISSN2376-5704
Autores Tópico(s)Metallurgical Processes and Thermodynamics
ResumoTh e " low te mperature stru cture type" of Ta, O. has bee n found to occur in two di stin c t forms with th e lowes t te mp e rature form hav in g a unit cell 14 tim es th e s ub ce ll a nd an inte rm ed ia ,e te mlJe ra ture form with a unit ce ll 11 tim es the subcell.Th e two t ypes form inte rm ediate partially ord ered mixtures which are appare ntl y in th e rmal equilibrium at various te mp e ratu res be twee n -1000 and 1350 °C.The additi on of Mo03, W03, SiO" CeO" ZrO" TiO" 8 , 0 3 and AI, 0 3 each affect the multiplicit y of th e tru e unit ce ll in differe nt ways.WO o, S iO" CeO" 8 2 0 3, and AI,03 fo rm phases stru cturall y similar to " !ow-T a,05' whi c h are sta bl e up to the sol idu s te mpe ratures of th e co rres pondin g syste ms.
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