A Truly Hard-To-Obtain Element ── Dysprosium

Introduction

Dysprosium was first isolated in 1886 by French chemist Paul Émile L. de Boisbaudran while studying erbium oxide in Paris. He named the new element “Dysprosium,” derived from the Greek word Dysprositos (δυσπρόσιτος), meaning “difficult to access,” highlighting its rarity.

Dysprosium found in nature consists of seven isotopes: ^156Dy, ^158Dy, and ^160Dy through ^164Dy, with ^164Dy being the most abundant. Scientists have synthesized 29 radioactive isotopes, the most stable being ^154Dy, while ¹³⁸Dy is the least stable. Additionally, dysprosium isotopes ^152Dy and ¹⁵⁹Dy primarily undergo electron capture as a decay process. Dysprosium also has at least 11 nuclear isomers, with ^165mDy being the most stable among them.

Dysprosium ranks as the ninth most abundant rare earth element in the Earth’s crust. It is primarily extracted from a mix of phosphates called monazite sands and bastnasite-(Ce) or is found in various ores such as xenotime, brown yttrium niobium, gadolinite, euxenite, polycrase, and toddite. The first pure form of dysprosium was isolated in the 1950s by F. Spedding at Iowa State University using ion-exchange technology.

Dysprosium (Dy)

Atomic number: 66

Atomic weight: 162.500 u

Atomic structure: The outermost electronic structure of dysprosium is 4f¹⁰ 6s²。

Physical/chemical properties: It is a metal with a bright silver luster and is soft enough to be cut with a knife. Without overheating, there will be no sparks during the processing. But even small amounts of impurities can significantly change the physical properties of dysprosium.

The Main Application Areas of Dysprosium

• Permanent Magnet Material: The addition of dysprosium can significantly improve the magnetic properties of neodymium-based permanent magnets by increasing coercivity, which enhances the magnet’s heat resistance. This allows for the generation of stronger magnetic fields and supports applications in electric motors, generators, wind turbines, electric vehicles, hard disk drives, and various magnetic devices.
  
• Optical Glass: Dysprosium is used in the manufacture of optical glass for high-performance optical lenses, fiber-optic communication components, and lasers. Dysprosium-enhanced optical glass offers superior optical qualities, including high refractive index and dispersion, which are essential for advanced optical devices.
  
• Nuclear Reactor Control Rods: ^164Dy is used as a control material in nuclear reactors due to its excellent neutron absorption, which helps regulate reaction rates—valuable in nuclear energy applications.
  
• Metal Alloys: Dysprosium nanoparticles enhance certain metal alloys, increasing their high-temperature resilience, a property valuable in aerospace and high-temperature applications.
  
• Magnetic Memory: Dysprosium was once used in some magnetic memory storage devices, although this application has decreased with advancing technology.
  
• Magnetostrictive Alloys: The material with the strongest magnetostrictive properties at room temperature is Terfenol-D, an alloy of dysprosium, iron, and terbium. Its unique magnetostrictive qualities make it suitable for transducers, broadband mechanical resonators, and high-precision liquid fuel injectors, where responsive mechanical transformation under magnetic influence is crucial.
  
• Adiabatic Demagnetization Refrigerator: Crystals of paramagnetic dysprosium salts, such as dysprosium gallium garnet (DGG), dysprosium aluminum garnet (DAG), and dysprosium iron garnet (DyIG), are used in adiabatic demagnetization refrigerators.
  
• Other Applications: Dysprosium is also applied in computer hard drives, lasers, metal halide lamps, and dysprosium-doped yttrium aluminum garnet (Dy), which is used in fiber optic temperature measurement systems and white LEDs.