title: Cation-Induced Variation of Micromorphology and Luminescence Properties of Tungstate Phosphors by a Hydrothermal Method.
abstract: Eu3+-doped MWO4(M = Zn, Cd, Ca, Sr, or Ba) nanorods and rodlike, spherical, dumbbell-like, and double-tapter-like grains have been obtained via a hydrothermal method. The distinct differences in cationic radius lead to a special morphology, which is attributed to the symmetry of the crystal structure and the differences in the growth rates of various crystals, and it further leads to the variation of luminescence. It was found that the charge transfer band of MWO4:0.04Eu3+exhibits a blue shift with an increasing cationic radius, and the shift is ascribed to less covalency being caused by an increase in the cationic radius. The emission intensity obviously increases with cationic radius, increasing for the samples with a monoclinic phase; however, it is the opposite for the samples with a tetragonal phase, and CaWO4:0.04Eu3+exhibits an optimal emission intensity. In addition, the possible reasons for the decay lifetime are also discussed in detail. Our results indicate that cations can effectively control the crystal structure, micromorphology, and luminescence in tungstate phosphors, and thus, our approach is effective for obtaining materials with the desired morphology and crystal structure.
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University , Chengdu 610066, China.
authors.forename: Lihua
authors.initials: L
authors.lastname: He
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University , Chengdu 610066, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zou
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University , Chengdu 610066, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University , Chengdu 610066, China.
authors.forename: Qiaoji
authors.initials: Q
authors.lastname: Zheng
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University , Chengdu 610066, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liao
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University , Chengdu 610066, China.
authors.forename: Chenggang
authors.initials: C
authors.lastname: Xu
authors.affiliation: Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201, China.
authors.forename: Yongfu
authors.identifier: http://orcid.org/0000-0002-9502-5897
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University , Chengdu 610066, China.
authors.forename: Dunmin
authors.identifier: http://orcid.org/0000-0002-2245-6717
authors.initials: D
authors.lastname: Lin