Open AccessStructure and formation mechanisms of (K0.46Na0.46La0.08)(Nb0.94Sb0.06)O3 particles under hydrothermal conditions
Author(s) -
Xingrui Li,
Xinwei Shi
Publication year - 2020
Publication title -
processing and application of ceramics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.326
H-Index - 15
eISSN - 2406-1034
pISSN - 1820-6131
DOI - 10.2298/pac2004346l
Subject(s) - materials science , orthorhombic crystal system , hydrothermal circulation , hydrothermal synthesis , crystal structure , dissolution , chemical engineering , crystal growth , recrystallization (geology) , doping , crystallography , mineralogy , chemistry , geology , paleontology , optoelectronics , engineering
(K0.46Na0.46La0.08)(Nb0.94Sb0.06)O3 powders were synthesized via hydrothermal method. The effects of differentreaction conditions on crystal structure, micro-morphology and phase formation were analysed by XRD andSEM in detail. The results reveal that (K0.46Na0.46La0.08)(Nb0.94Sb0.06)O3 powders with orthorhombic latticestructure are synthesized at 200?C for 18 h with the total initial alkali concentration of 8mol/l. The averageparticle size of synthesized powders is about 500-700 nm, which has regular cubic morphology with uniformdistribution. Moreover, doping with La3+ and Sb5+ inhibits the crystal growth. The phase evolution of the powdersrevealed that the hydrothermal synthesis of (K0.46Na0.46La0.08)(Nb0.94Sb0.06)O3 underwent two steps, wherean intermediate product of K4Na4Nb6O19? 9H2O was found in the early stage at 140?C. Based on the results,the formation mechanism of (K0.46Na0.46La0.08)(Nb0.94Sb0.06)O3 powders was proposed. It can be inferred thatthe crystal growth model of (K0.46Na0.46La0.08)(Nb0.94Sb0.06)O3 is dissolution-crystal growth-recrystallizationwith the characteristics of layered growth.