Dysprosium - 66Dy: the essentials
- Name: dysprosium
- Symbol: Dy
- Atomic number: 66
- Relative atomic mass (Ar): 162.500 (1) g [see note g]
- Standard state: solid at 298 K
- Appearance: silvery white
- Classification: Metallic
- Group in periodic table:
- Group name: Lanthanoid
- Period in periodic table: 6 (lanthanoid)
- Block in periodic table: f
- Shell structure: 2.8.18.28.8.2
- CAS Registry: 7429-91-6
Dysprosium atoms have 66 electrons and the shell structure is 2.8.18.28.8.2. The ground state electronic configuration of neutral dysprosium is [Xe].4f10.6s2 and the term symbol of dysprosium is 5I8.
Dysprosium: description
Dysprosium has a metallic, bright silver lustre. It is relatively stable in air at room temperature, but dissolves readily, with the evolution of hydrogen, in mineral acids. The metal is soft enough to be cut with a knife and can be machined without sparking if overheating is avoided. It is a rare earth metal found in minerals such as xenotime, monazite and bastnaesite.
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Dysprosium: physical properties
Density of solid: 8551 kg m-3
Molar volume: 19.01 cm3
Thermal conductivity: 11 W m‑1 K‑1
Dysprosium: heat properties
Melting point: 1680 [1407 °C (2565 °F)] K
Boiling point: 2840 [2567 °C (4653 °F)] K
Enthalpy of fusion: 20.5 kJ mol-1
Dysprosium: atom sizes
Atomic radius (empirical): 175 pm
Molecular single bond covalent radius: 167 (coordination number 3) ppm
van der Waals radius: 281 ppm
Dysprosium: electronegativities
Pauling electronegativity: 1.22 (Pauling units)
Allred Rochow electronegativity: 1.10 (Pauling units)
Mulliken-Jaffe electronegativity: (no data)
Dysprosium: orbital properties
First ionisation energy: 573.03 kJ mol‑1
Second ionisation energy: 1123.8 kJ mol‑1
Third ionisation energy: 2210 kJ mol‑1
Dysprosium: abundances
Universe: 2 ppb by weight
Crustal rocks: 6200 ppb by weight
Human: (no data) ppb by weight
Dysprosium: crystal structure
Dysprosium: biological data
- Human abundance by weight: (no data) ppb by weight
Dysprosium has no biological role.
Dysprosium: uses
Dysprosium: reactions
Reactions of dysprosium as the element with air, water, halogens, acids, and bases where known.
Dysprosium: binary compounds
Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of dysprosium where known.
Dysprosium: compound properties
Bond strengths; lattice energies of dysprosium halides, hydrides, oxides (where known); and reduction potentials where known.
Dysprosium: history
Dysprosium was discovered by Paul Emile Lecoq de Boisbaudran in 1886 at France. Origin of name: from the Greek word "dysprositos" meaning "hard to obtain".Dysprosium: isotopes
Many of the Dy isotopes have been the subject of physics research. Dy-156 has been used to study double electron capture while Dy-160 has been used in research to investigate its multitude of excited states. Dy-161 spectroscopy has been used to determine the properties of Dy based superconductor material. Dy-162 has been used to study excited states in deformed nuclei. Dy-164 has two medical applications. It is used in the production of Dy-165 which is used in arthritis therapy. Dy-164 is also used for the production of Dy-166 which decays to Ho-166 and this used in cancer therapy. The Dy-164 to Ho-166 route gives the advantage of generating so-called carrier free material.
Dysprosium: isolation
Isolation: dysprosium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive.
For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography.
Pure dysprosium is available through the reduction of DyF3 with calcium metal.
2DyF3 + 3Ca → 2Dy + 3CaF2
This would work for the other calcium halides as well but the product CaF2 is easier to handle under the reaction conditions (heat to 50°C above the melting point of the element in an argon atmosphere). Excess calcium is removed from the reaction mixture under vacuum.