Open AccessAmorphous Zr(OH)4 to t-ZrO2 transformed isothermally
Author(s) -
Jonathan Meza Galvez,
Oscar Olea-Mejía,
Susana Hernández López,
Enrique Vigueras-Santiago,
Marco A. López
Publication year - 2018
Publication title -
superficies y vacío
Language(s) - English
Resource type - Journals
ISSN - 1665-3521
DOI - 10.47566/2018_syv31_1-030044
Subject(s) - amorphous solid , isothermal process , materials science , exothermic reaction , crystallization , raman spectroscopy , differential scanning calorimetry , phase (matter) , analytical chemistry (journal) , chemical engineering , thermodynamics , crystallography , chemistry , organic chemistry , optics , physics , engineering
With the aim to study the transformation from the commercially amorphous Zr(OH)4 to the t-ZrO2, phase, the starting material was isothermally treated in a calorimeter at 350, 365, 370, 375 and 380 o C. The TGA coupled to the DSC technique was used to determine with high precision both the temperature and time necessary to achieve the amorphous Zr(OH)4 to t-ZrO2 transformation. The mass loss and heat flow, as a function of time, were monitored to study the dehydroxylation of Zr(OH)4 and the crystallization processes, respectively. Raman spectroscopy was used to obtain evidence of the t-ZrO2 formation. The DSC results show an exothermic peak (typical of amorphous-crystalline transitions) related to the formation of t-ZrO2. Our results indicate that the time necessary to obtain the t-ZrO2 phase shortens when temperature increases.