About: Lanthanide is a(n) research topic. Over the lifetime, 15924 publication(s) have been published within this topic receiving 402161 citation(s). The topic is also known as: rare earths & lanthanide series.
Koen Binnemans1•Institutions (1)
TL;DR: The results suggest that the doping-induced structural and size transition, demonstrated here in NaYF4 upconversion nanocrystals, could be extended to other lanthanide-doped nanocrystal systems for applications ranging from luminescent biological labels to volumetric three-dimensional displays.
Abstract: Doping is a widely applied technological process in materials science that involves incorporating atoms or ions of appropriate elements into host lattices to yield hybrid materials with desirable properties and functions. For nanocrystalline materials, doping is of fundamental importance in stabilizing a specific crystallographic phase, modifying electronic properties, modulating magnetism as well as tuning emission properties. Here we describe a material system in which doping influences the growth process to give simultaneous control over the crystallographic phase, size and optical emission properties of the resulting nanocrystals. We show that NaYF(4) nanocrystals can be rationally tuned in size (down to ten nanometres), phase (cubic or hexagonal) and upconversion emission colour (green to blue) through use of trivalent lanthanide dopant ions introduced at precisely defined concentrations. We use first-principles calculations to confirm that the influence of lanthanide doping on crystal phase and size arises from a strong dependence on the size and dipole polarizability of the substitutional dopant ion. Our results suggest that the doping-induced structural and size transition, demonstrated here in NaYF(4) upconversion nanocrystals, could be extended to other lanthanide-doped nanocrystal systems for applications ranging from luminescent biological labels to volumetric three-dimensional displays.
•01 Jan 1976
Abstract: FIRST PRINCIPLES Some Preliminaries The Electronic Structure of Atoms Structure and Bonding in Molecules Ionic Solids The Chemistry of Selected Anions Coordination Chemistry Solvents, Solutions, Acids and Bases The Periodic Table and the Chemistry of the Elements THE MAIN GROUP ELEMENTS Hydrogen The Group IA(1) Elements: Lithium, Sodium, Potassium, Rubidium and Cesium The Group IIA(2) Elements: Beryllium, Magnesium, Calcium, Strontium and Barium Boron The Group IIIB(13) Elements: Aluminum, Gallium, Indium and Thallium Carbon The Group IVB(14) Elements: Silicon, Germanium, Tin and Lead Nitrogen The Group VB(15) Elements: Phosphorus, Arsenic, Antimony and Bismuth Oxygen The Group VIB(16) Elements: Sulfur, Selenium, Tellurium and Polonium The Halogens: Fluorine, Chlorine, Bromide and Astatine The Noble Gases Zinc, Cadmium and Mercury THE TRANSITION ELEMENTS Introduction to Transition Elements: Ligand Field Theory The Elements of the First Transition Series The Elements of the Second and Third Transition Series Scandium, Yttrium, Lanthanum and the Lanthanides The Actinide Elements SOME SPECIAL TOPICS Metal Carbonyls and Other Transition Metal Complexes with TT-Acceptor (TT-Acid) Ligands Organometallic Compounds Stoichiometric and Catalytic Reactions of Organometallic Compounds Bio-Inorganic Chemistry Index.
TL;DR: Double-decker phthalocyanine complexes with Tb3+ or Dy3+ showed slow magnetization relaxation as a single-molecular property and a significant temperature rise results from a mechanism in the relaxation process different from that in the transition-metal-cluster SMMs.
Abstract: Double-decker phthalocyanine complexes with Tb3+ or Dy3+ showed slow magnetization relaxation as a single-molecular property. The temperature ranges in which the behavior was observed were far higher than that of the transition-metal-cluster single-molecule magnets (SMMs). The significant temperature rise results from a mechanism in the relaxation process different from that in the transition-metal-cluster SMMs. The effective energy barrier for reversal of the magnetic moment is determined by the ligand field around a lanthanide ion, which gives the lowest degenerate substate a large |Jz| value and large energy separations from the rest of the substates in the ground-state multiplets.