rare-earth element

Table of Contents

Introduction
Discovery and history
Abundance, occurrence, and reserves
Minerals and ores
- Bastnasite
- Laterite clays
- Monazite
- Loparite
- Xenotime
Electronic structure and ionic radius
Processing ores
Separation chemistry
- Ion exchange
- Solvent extraction
Preparation of the metals
- Calciothermic method
- Electrolytic method
- Preparation of samarium, europium, thulium, and ytterbium: lanthanothermic process
Properties of the metals
- Crystal structures
- Melting points
- Boiling points
- Electrical properties
- Magnetic properties
- Thermal expansion
- Elastic properties
- Mechanical properties
- Chemical properties
Compounds
- Oxides
  - Sesquioxides
  - Higher oxides
  - Lower oxides
  - Ternary and higher-order oxides
- Hydrides
- Halides
- Metallic and complex compounds
  - Permanent magnets
  - Rechargeable batteries
  - Electron guns
  - Microkelvin cooling
  - Magnetostriction
  - Giant magnetocaloric effect
- Complexes
Nuclear properties
Toxicity

References & Edit History Quick Facts & Related Topics

Images

electron probabilities for gadolinium

melting points and transformation temperatures

Crystal structures of rare-earth metals.

linear coefficient of thermal expansion

free energy of formation of rare-earth sesquioxides

The arrangement of copper, yttrium, oxygen, and barium ions in yttrium barium copper oxide (YBa2Cu3O7), an example of a superconducting ceramic crystal structure.

For Students

rare earth metal summary

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rare-earth element: Facts & Related Content

Written and fact-checked by The Information Architects of Encyclopaedia Britannica

News •

A Toxic Pit Could Be a Gold Mine for Rare-Earth Elements • May 14, 2025, 8:08 AM ET (New York Times)

Energy Fuels Announces Q3-2024 Results, Including Active Uranium Mining and Processing, Successful Rare Earth Production, and Continuing to Build a World-Scale Rare Earth Supply Chain Centered in the U.S. • May 4, 2025, 6:05 AM ET (Globe and Mail)

Tesla’s Humanoid Robot Plan Disrupted by China Rare Earth Curbs • Apr. 23, 2025, 5:20 AM ET (Bloomberg.com)

Facts

Also Known As	rare-earth metal • inner transition element

Photos

electron probabilities for gadolinium

melting points and transformation temperatures

Crystal structures of rare-earth metals.

linear coefficient of thermal expansion

free energy of formation of rare-earth sesquioxides

The arrangement of copper, yttrium, oxygen, and barium ions in yttrium barium copper oxide (YBa2Cu3O7), an example of a superconducting ceramic crystal structure.

See All Images →

Topics

transition metal gadolinium cerium lanthanum samarium neodymium ytterbium scandium terbium yttrium hydrogen alkali metal alkaline-earth metal carbon group element boron group element oxygen group element nitrogen group element halogen noble gas zinc group element

Key People

Carl Gustaf Mosander

Swedish chemist

Frank Harold Spedding

American chemist

Quiz

Periodic table of the elements. Left column indicates the subshells that are being filled as atomic number Z increases. The body of the table shows element symbols and Z. analysis and measurement

Periodic Table of the Elements

Periodic Table of the elements concept image (chemistry)

Facts You Should Know: The Periodic Table Quiz

Periodic Table of the elements concept image (chemistry)

Facts You Should Know: The Periodic Table Quiz