Preparation And Luminescence Properties Of Low-dimensional Rare Earth Fluoride Nanomaterials

Rare earth trifluoride is a high efficient matrix for rare earth ion-doped luminescent materials owing to its low vibrational energies. It has been extensively applied in the fields of medical testing, anti-fake, lighting, display, etc. Nowadays, research of rare earth fluoride nanomaterials is focused on nanoparticles, nanorods and nanotubes. There are no reports on the rare earth fluoride nanofibers and nanobelts. In order to study their properties, preparation technique of rare earth trifluoride nanofibers and nanobelts is urgently needed. Electrospinning is the best choice due to its simple and highly reproducible process in the fabrication of one-dimentional nanomaterials. Therefore, fabrication of rare earth ions-doped rare earth trifluoride nanofibers and nanobelts via electrospinning will be a meaningful subject of significance.PVP nanomaterials with various morphologies fabricated by electrospinning are studied in this dissertation. Diagram of the relationship between solution parameters and morphologies distribution zone of the prepared products was also drawn for the first time. The diagram is universally applicable and can be used to design relevant experiments. Under the direction of this diagram, PVP was used as template to fabricate Y2O3:Eu3+ nanofibers and nanobelts and YF3:Eu3+ nanofibers and nanobelts. Then YOF:Eu3+ nanofibers, u3+ nanofibers and nanobelts and Y7O6F9:Tb3+ nanobelts were obtained by calcining the obtained YF3:RE3+(RE=Eu, Tb). Lumenscence properties of these nanomaterials were studied.The samples were characterized by XRD, FTIR, SEM, TEM and PL. Results show that cubic Y2O3:Eu3+ nanomaterials were prepared by calcination of PVP/[rare earth nitrate] composite nanomaterials at 700℃for 8 h, YF3:Eu3+ nanomaterials were synthesized by fluorization of the relevant Y2O3:Eu3+ nanomaterials using NH4HF2 as fluorinating agent. Rhombohedral YOF:Eu3+ nanomaterials were acquired by calcining YF3:Eu3+nanomaterials at 700℃for 9 h. Orthorhombic Y7O6F9:Eu3+ nanomaterials were obtained by calcining YF3:Eu3+ nanomaterials at 580℃for 9 h. Diameters of these fibers are 70-200 nm. Widths of these nanobelts are 3-10μn, and the thickenss of these nanobelts are 80-200 nm. The strongest emission peaks of Y2O3:Eu3+, YOF:Eu3+ and Y7O6F9:Eu3+ nanomaterials were originating from 5D0â†'7F2, but the strongest emission peak of YF3:Eu3+ nanomaterials was originating from 5D0â†'7F1. Y7O6F9:Eu3+ nanomaterials have the strongest emission spectrum.