Yttrium Y

spore: profile
id: yttrium
spore_version: 0.2
family: rare-earth-metals
name: Yttrium
abbreviation: 'Y'
role: phosphor and laser-crystal element, and an alloy addition for magnesium and other metals
category: metals
type: heavy-metals
summary: |
  Yttrium is the element Y (atomic number 39), a silvery transition metal with a density of 4.469 g/cm3 that melts at 1526 °C. It is always found in nature with the lanthanides, in minerals such as monazite and xenotime, and is recovered with them. Its largest present-day use is in phosphors, including the LED phosphor YAG:Ce and the red phosphors of colour television tubes. USGS lists ceramics and phosphors as the leading end uses, and yttrium-aluminum-garnet crystals are used in lasers. Small additions of about 4 % yttrium make the WE43B magnesium casting alloy suitable for hot aerospace parts, and the metal is used in other alloys to improve high-temperature oxidation resistance.
best_for: 'Phosphors and laser-crystal hosts, where yttrium is in the oxide or garnet form (USGS: no direct substitute in most electronics, laser and phosphor uses)'
weakest_at: Fine powder and turnings, which ignite in air (Wikipedia, CRC) and react with water to release hydrogen (Apollo Scientific SDS). Its supply is 100 % import-dependent for the United States (USGS).
identity:
  formula: Y (element, atomic number 39); the metal is sold as powder, chips, ingot, rod or foil, and its compounds are mainly the oxide Y2O3 (yttria)
  cas: 7440-65-5
  crystal_system: hexagonal close-packed (hcp)
  lattice_constants: a = 364.83 pm, c = 573.17 pm at 20 °C
  source: pubchem-y
  where: Names and Identifiers, Other Identifiers, CAS (PubChem CID 23993); crystal structure and lattice constants from the Wikipedia infobox
  designations: []
tags:
  applications:
    - electronics-and-chips
    - optics-and-cameras
    - structures
properties:
  - benchmark: density
    label: Density, yttrium at 20 °C
    value: 4.469
    unit: g/cm3
    scope: material
    conditions:
      temperature: 20 °C
      unit_in_source: 4.469 g/cm3 (at 20 °C)
    method: Value printed in the Wikipedia infobox, with a citation to the CRC Handbook
    status: ground
    source: wiki-y
    where: Infobox, Physical properties, row Density (at 20 °C)
  - benchmark: density
    label: Density, yttrium powder at 20 °C
    value: 4.47
    unit: g/cm3
    scope: material
    conditions:
      temperature: 20 °C
      form: powder
      unit_in_source: 4.47 g/cm³ at 20 °C (68 °F)
    method: Value printed in a supplier safety data sheet, section 9
    status: ground
    source: sam-powder-sds
    where: Section 9 Physical and chemical properties, Density at 20 °C
  - benchmark: melting_point
    label: Melting point, yttrium
    value: 1526
    unit: °C
    scope: material
    conditions:
      pressure: not stated
      unit_in_source: 1799 K (1526 °C, 2779 °F)
    method: Value printed in the Wikipedia infobox
    status: ground
    note: The supplier SDS prints 1522 °C and PubChem prints 1522 °C and 1526 °C in different entries. The Wikipedia value is recorded, and the 1522 °C value is entered below.
    source: wiki-y
    where: Infobox, Physical properties, row Melting point
  - benchmark: melting_point
    label: Melting point, yttrium powder (literature value)
    value: 1522
    unit: °C
    scope: material
    conditions:
      form: powder
      unit_in_source: 1522 °C (2772 °F)
    method: Value printed in a supplier safety data sheet, section 9
    status: ground
    source: sam-powder-sds
    where: Section 9 Physical and chemical properties, Melting point/range
  - benchmark: boiling_point
    label: Boiling point, yttrium
    value: 2930
    unit: °C
    scope: material
    conditions:
      pressure: not stated in the infobox
      unit_in_source: 3203 K (2930 °C, 5306 °F)
    method: Value printed in the Wikipedia infobox
    status: ground
    note: The supplier SDS prints 3338 °C and PubChem prints 3345 °C at 760 mmHg. The sources differ by about 400 °C, so this profile records the Wikipedia infobox value and does not reconcile the others.
    source: wiki-y
    where: Infobox, Physical properties, row Boiling point
  - benchmark: thermal_conductivity
    label: Thermal conductivity, yttrium
    value: 17.2
    unit: W/(m·K)
    scope: material
    conditions:
      temperature: not stated in the infobox
      unit_in_source: 17.2 W/(m⋅K)
    method: Value printed in the Wikipedia infobox
    status: ground
    source: wiki-y
    where: Infobox, Physical properties, row Thermal conductivity
  - benchmark: specific_heat
    label: Specific heat capacity, yttrium
    value: 298.405
    unit: J/(kg·K)
    scope: material
    conditions:
      temperature: not stated in the infobox
      unit_in_source: 298.405 J/(kg·K)
    method: Value printed in the Wikipedia infobox; equal to about 0.298 J/(g·K)
    status: ground
    source: wiki-y
    where: Infobox, Physical properties, row Specific heat capacity
  - benchmark: cte
    label: Coefficient of thermal expansion, yttrium at 20 °C
    value: 11.21
    unit: ppm/K
    scope: material
    conditions:
      temperature: 20 °C
      unit_in_source: 11.21 × 10−6/K (at 20 °C)
    method: Value printed in the Wikipedia infobox; 10−6/K is the same unit as ppm/K
    status: ground
    source: wiki-y
    where: Infobox, Physical properties, row Thermal expansion
  - benchmark: elastic_modulus
    label: Young's modulus, yttrium
    value: 63.5
    unit: GPa
    scope: material
    conditions:
      temperature: not stated in the infobox
    method: Value printed in the Wikipedia infobox, Elastic properties
    status: ground
    source: wiki-y
    where: Infobox, Elastic properties, row Young's modulus
  - benchmark: shear_modulus
    label: Shear modulus, yttrium
    value: 25.6
    unit: GPa
    scope: material
    conditions:
      temperature: not stated in the infobox
    method: Value printed in the Wikipedia infobox, Elastic properties
    status: ground
    source: wiki-y
    where: Infobox, Elastic properties, row Shear modulus
  - benchmark: bulk_modulus
    label: Bulk modulus, yttrium
    value: 41.2
    unit: GPa
    scope: material
    conditions:
      temperature: not stated in the infobox
    method: Value printed in the Wikipedia infobox, Elastic properties
    status: ground
    source: wiki-y
    where: Infobox, Elastic properties, row Bulk modulus
  - benchmark: poissons_ratio
    label: Poisson's ratio, yttrium
    value: 0.243
    unit: '-'
    scope: material
    conditions:
      temperature: not stated in the infobox
    method: Value printed in the Wikipedia infobox, Elastic properties
    status: ground
    source: wiki-y
    where: Infobox, Elastic properties, row Poisson ratio
  - benchmark: electrical_resistivity
    label: Electrical resistivity, yttrium at room temperature
    value: 596
    unit: nΩ·m
    scope: material
    conditions:
      temperature: room temperature
      unit_in_source: 596 nΩ⋅m (at room temperature)
      polymorph_label: alpha, poly (the infobox label, as printed)
    method: Value printed in the Wikipedia infobox
    status: ground
    note: The infobox gives the label "α, poly" for this row. It is entered as printed, and the polymorph it refers to is not stated in the source.
    source: wiki-y
    where: Infobox, Physical properties, row Electrical resistivity
  - benchmark: brinell_hardness
    label: Brinell hardness, yttrium
    value: 200
    value_high: 589
    bound: range
    unit: MPa
    scope: material
    conditions:
      temperature: not stated in the infobox
      unit_in_source: 200–589 MPa
    method: Range printed in the Wikipedia infobox; the source does not state the test load or the purity
    status: ground
    note: No canonical name exists for hardness in the property file, so brinell_hardness is a new name and is listed in gaps.
    source: wiki-y
    where: Infobox, Mechanical properties, row Brinell hardness
corrosion:
  - environment: Air at room temperature, bulk metal
    headline: Bulk yttrium is stable in air because a thin oxide film forms on its surface.
    effect: Wikipedia says the bulk metal is relatively stable in air because of passivation by a protective Y2O3 film. The film can reach 10 µm thick when yttrium is heated to 750 °C in water vapour. PubChem says the same oxide-film stability applies to bulk yttrium in air.
    rating: low
    conditions:
      form: bulk metal
      temperature: room temperature
    source: wiki-y
    where: Chemical properties, first paragraph on passivation; PubChem Stability and Reactivity, Reactivity Profile
  - environment: Cold and boiling water
    headline: Yttrium decomposes slowly in cold water and quickly in boiling water, releasing hydrogen.
    effect: PubChem records that yttrium decomposes in cold water slowly and in boiling water rapidly, and that it reacts with water to form gaseous hydrogen. Apollo Scientific's SDS for the 40-mesh powder says the powder reacts slowly with water in one section and in contact with water releases flammable gases in its hazard statement H261.
    rating: moderate
    conditions:
      temperature: cold and boiling water
    source: pubchem-y
    where: Other Experimental Properties; Reactivity Profile
  - environment: Hot nitrogen at about 1000 °C
    headline: Yttrium forms the nitride when heated to 1000 °C in nitrogen.
    effect: Wikipedia says yttrium nitride (YN) forms when the metal is heated to 1000 °C in nitrogen. The source gives no rate or extent.
    rating: moderate
    conditions:
      temperature: 1000 °C
      atmosphere: nitrogen
    source: wiki-y
    where: Chemical properties, first paragraph on passivation
  - environment: Acids
    headline: Yttrium resists concentrated nitric and hydrofluoric acid, but other strong acids attack it.
    effect: Wikipedia says concentrated nitric and hydrofluoric acids do not rapidly attack yttrium, but other strong acids do. PubChem says yttrium is soluble in dilute acids and in potassium hydroxide solution, and is soluble in hot water.
    rating: moderate
    conditions:
      temperature: not stated
    source: wiki-y
    where: Chemical properties, paragraph on acids; PubChem Experimental Properties, Solubility
  - environment: Finely divided yttrium in air
    headline: Shavings, turnings and fine powder can ignite in air.
    effect: Wikipedia says shavings or turnings of the metal can ignite in air at temperatures above 400 °C, citing the CRC Handbook. The 40-mesh powder SDS from Stanford Advanced Materials classifies it as pyrophoric, with the hazard statement H250 that it catches fire spontaneously if exposed to air.
    rating: severe
    conditions:
      form: shavings, turnings and powder
      temperature: above 400 °C (shavings or turnings, Wikipedia)
    source: sam-y40-sds
    where: Section 2 Hazards identification, hazard statement H250; Wikipedia, Chemical properties
risks:
  hazards:
    - text: 'PubChem reports the ECHA C&L notifications: H228 (31.2 %, flammable solid), H250 (15.5 %, catches fire spontaneously if exposed to air), H302 (14.8 %, harmful if swallowed), with signal word Danger. It also lists a Warning notification with H371 (may cause damage to organs). Of 317 company reports, 180 (56.8 %) say the substance does not meet GHS criteria, so classification depends on the form and notifier.'
      ghs:
        - H228
        - H250
        - H302
        - H371
      source: pubchem-y
      where: Safety and Hazards, Hazards Identification, GHS Classification
    - text: 'Stanford Advanced Materials 40-mesh powder SDS (version 3.0, 2017): flammable solid H228, pyrophoric solid H250, and H302 plus H312 plus H332 (harmful if swallowed, in contact with skin or if inhaled), signal word Danger.'
      ghs:
        - H228
        - H250
        - H302
        - H312
        - H332
      source: sam-y40-sds
      where: Section 2.1 and 2.2 Classification and Label elements; Section 3 Hazardous components
    - text: 'Stanford Advanced Materials yttrium powder SDS (revised 2023): classified as flammable solid H228 only, signal word Danger. The SDS prints no pyrophoric classification and no H250 statement.'
      ghs:
        - H228
      source: sam-powder-sds
      where: Section 2 Hazards identification, GHS label elements
    - text: 'Apollo Scientific SDS for the 40-mesh powder (issue 2022): pyrophoric solid H250, flammable solid H228, and H261 (in contact with water releases flammable gases). The SDS lists the shipping name METAL POWDER, FLAMMABLE, N.O.S.'
      ghs:
        - H250
        - H228
        - H261
      source: apollo-y-sds
      where: Section 2, Classification and hazard statements; Section 14 shipping name
    - text: 'Materion yttrium metal SDS (2015): flammable solid Category 2 with signal word Warning, and causes eye irritation (Category 2B). This is a lower classification than the Stanford and Apollo powder SDSs.'
      ghs:
        - H228
      source: materion-y-sds
      where: Section 2 Hazard(s) identification, Physical hazards and Label elements
  failure_risks:
    - mode: Fire in fines and turnings
      trigger: Finely divided yttrium such as powder, shavings or turnings exposed to air
      consequence: Shavings or turnings can ignite in air at temperatures above 400 °C (Wikipedia, citing CRC). The 40-mesh powder SDS classifies the powder as pyrophoric (H250) and as a flammable solid (H228).
      severity: critical
      source: sam-y40-sds
      where: Section 2.2, hazard statement H250; Wikipedia, Chemical properties, first paragraph
    - mode: Reaction with water
      trigger: Yttrium powder or fines in contact with water
      consequence: PubChem says yttrium reacts with water to form gaseous hydrogen. The 40-mesh powder SDS says the powder reacts violently with water (Section 10.3), and the Apollo SDS says contact releases flammable gases (H261). Both SDSs say not to use water on a fire.
      severity: critical
      source: pubchem-y
      where: Stability and Reactivity, Reactivity Profile; Apollo SDS hazard statement H261
    - mode: Lung and eye irritation from dust
      trigger: Inhalation of dust or fume, or eye contact
      consequence: NIOSH, as summarised by PubChem, lists irritation of the eyes and pulmonary irritation in animals. An ECHA notification prints H371 for single-exposure lung effects. The OSHA permissible exposure limit is 1 mg/m3 as Y.
      severity: moderate
      source: pubchem-y
      where: Hazards Identification, Health Hazards; Exposure Control, Permissible Exposure Limit
    - mode: Nitride formation at high temperature
      trigger: Yttrium heated to 1000 °C in nitrogen
      consequence: Yttrium nitride (YN) forms (Wikipedia). The source gives no effect on properties.
      severity: low
      source: wiki-y
      where: Chemical properties, first paragraph
  side_effects:
    - text: The United States has no fully commercial facility that can separate or refine yttrium, so almost all yttrium metal and compounds are imported. Nearly all of those imports come from mineral concentrates processed in China (USGS).
      affects: Supply and price of yttrium metal in the United States
      source: usgs-y
      where: Domestic Production and Use; Import Sources (2021 to 2024)
  handling:
    - text: Store and handle under a dry protective gas or dry inert gas. Keep the container tightly sealed in a cool, dry place, away from air and water (Stanford Advanced Materials SDS, Section 7).
      source: sam-powder-sds
      where: Section 7 Handling and storage
    - text: Use a special powder for metal fires, dry sand, graphite powder or a dry sodium-chloride based extinguisher. Do not use water, CO2 or foam (Apollo Scientific SDS). The Stanford powder SDS also says do not use water. Materion's SDS lists water fog among its extinguishing media, so the suppliers disagree.
      source: apollo-y-sds
      where: Section 5.1 Extinguishing media
    - text: Keep away from heat, sparks and open flames, ground and bond containers and receiving equipment, and use explosion-proof equipment (Stanford 40-mesh powder SDS, P210, P240, P241).
      source: sam-y40-sds
      where: Section 2.2 Precautionary statements
    - text: 'Where dust forms, use a respirator. PubChem summarises the NIOSH guidance: up to 10 mg/m3, any particulate respirator with an N95, R95 or P95 filter. The OSHA and ACGIH limit is 1 mg/m3 as Y, and the immediately dangerous to life or health level is 500 mg Y/m3 (NIOSH).'
      source: pubchem-y
      where: Exposure Control and Personal Protection, Respirator Recommendations; Permissible Exposure Limit; IDLH
  mitigations: []
uses:
  - application: electronics-and-chips
    device: Phosphors in LEDs and colour television tubes (YAG:Ce and europium-doped yttria)
    example: Wikipedia says the most important present-day use of yttrium is as a component of phosphors, especially those used in LEDs. The red phosphors of colour cathode ray tubes were yttria or yttrium oxysulfide doped with europium, and cerium-doped YAG crystals are used as a phosphor.
    source: wiki-y
    where: Lead paragraph; Phosphors section, paragraph on the red component of colour cathode ray tubes; Garnets section
  - application: optics-and-cameras
    device: Yttrium-aluminium-garnet (YAG) laser crystals
    example: USGS says the leading end uses of yttrium are in ceramics and phosphors, and that yttrium-aluminum-garnet crystals are used in lasers for communication, industrial and medical applications.
    source: usgs-y
    where: Domestic Production and Use, first and second paragraphs
  - application: structures
    device: WE43B magnesium casting alloy with about 4 % yttrium
    example: The Luxfer datasheet page for WE43B prints the chemical composition as yttrium 3.7 to 4.3 %, and says it is for designers of aeroengines and other power systems, helicopter transmissions, missiles, and racing and high-performance cars.
    source: luxfer-we43b
    where: Product description, Applications; Chemical composition
supply:
  - subject: Yttrium abundance in the Earth
    abundance: About 31 ppm of the Earth's crust (Wikipedia, citing Cotton 2006). Soil contains 10 to 150 ppm (dry-weight average 23 ppm), and sea water about 9 ppt.
    producers: []
    critical_lists: []
    source: wiki-y
    where: Occurrence, first paragraph and Abundance paragraph
  - subject: Yttrium critical-mineral listing
    producers: []
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (final list, read through a fetch summary of the USGS page)
        listed: true
    source: usgs-crit2025
    where: 'Final 2025 List, entry Yttrium: used in lighting and display technologies and in high-performance metal alloys. Read through a fetched summary, not raw page text.'
  - subject: Yttrium metal and compounds, U.S. imports (2021 to 2024)
    producers:
      - country: China
        share_percent: 70
        year: 2024
      - country: Germany
        share_percent: 11
        year: 2024
      - country: Austria
        share_percent: 8
        year: 2024
      - country: Republic of Korea
        share_percent: 4
        year: 2024
    critical_lists: []
    recycling: 'USGS: insignificant.'
    substitutes:
      - 'USGS: substitutes exist for some uses but are generally much less effective. In most uses, especially electronics, lasers and phosphors, yttrium is not directly substituted. As a stabilizer in zirconia, yttria may be replaced by calcium oxide or magnesium oxide, but the substitutes give lower toughness.'
    source: usgs-y
    where: Import Sources (2021 to 2024), with other sources at 7 %; Recycling; Substitutes. Shares are import shares, not production shares. The year field is 2024 for the 2021 to 2024 period.
media: []
documents:
  - title: 'USGS Mineral Commodity Summaries 2026: Yttrium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-yttrium.pdf
    year: 2026
  - title: PubChem compound record for yttrium (CID 23993), including ECHA C&L Inventory classification
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23993
    year: 2026
  - title: 'Wikipedia: Yttrium'
    type: database
    url: https://en.wikipedia.org/wiki/Yttrium
    year: 2026
  - title: Safety data sheet, yttrium powder (Stanford Advanced Materials, revised 2023)
    type: sds
    url: https://samaterials.com/tds/1697121527-1311-yttrium-powder-y-powder-spherical-sds.pdf
    year: 2023
  - title: Safety data sheet, yttrium powder -40 mesh (Stanford Advanced Materials, version 3.0)
    type: sds
    url: https://samaterials.com/tds/1711612168-YM1089-Yttrium-Metal-Powder-(Y-Metal-Powder)-sds.pdf
    year: 2017
  - title: Materion safety data sheet, yttrium metal (SDS Y-MSDS0013, issued 2015), copy hosted by Purdue PRIME Lab
    type: sds
    url: https://www.physics.purdue.edu/primelab/safety/MSDS/SDS/yttriem%20metal%20%20-%20Materion.pdf
    year: 2015
  - title: Apollo Scientific safety data sheet, yttrium powder -40 mesh (IN3826, issue 2022)
    type: sds
    url: https://store.apolloscientific.co.uk/storage/msds/IN3826_msds.pdf
    year: 2022
  - title: 'Luxfer MEL Technologies: Elektron WE43B magnesium casting alloy (product page)'
    type: datasheet
    url: https://www.luxfermeltechnologies.com/elektron-we43b/
  - title: 'USGS: About the 2025 List of Critical Minerals'
    type: report
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
gaps:
  - 'Physical properties: the Wikipedia infobox is the only source for the elastic constants, thermal conductivity, specific heat, thermal expansion, electrical resistivity and Brinell hardness. No second source for those was opened in this run, so they are single-source values.'
  - 'Brinell hardness: brinell_hardness is a new name because the property file has no canonical name for hardness. The infobox prints a range of 200 to 589 MPa without a test load.'
  - 'Boiling point: Wikipedia gives 2930 °C, the Stanford SDS gives 3338 °C and PubChem gives 3345 °C at 760 mmHg. The sources differ and are not reconciled.'
  - 'World production: USGS gives 10,000 to 15,000 tons (Y2O3 equivalent) of world mine production for 2025 and says China produced most of the supply, with Burma a significant producer. No country share is printed, so no producers row is entered for world production.'
  - 'Critical-mineral listing: the USGS 2025 list page returned a 919-byte response when fetched directly, so the yttrium entry was read through a fetch summary. Confirm the wording on the page. The EU critical raw materials page names heavy rare earth elements as a group and does not name yttrium, so no EU row is entered.'
  - 'Space use: no flight, vacuum, radiation or spacecraft use of yttrium metal was found in the sources read. The WE43B alloy use is for aero-engine and helicopter parts (Luxfer), not a named spacecraft.'
  - 'Grade codes: no UNS, EN or other standard grade code for yttrium metal was printed in the sources read. The SDSs describe the product as a laboratory chemical, not a standard alloy grade, so designations is empty.'
  - 'Media: no image was fetched with its license checked, so media is empty.'
  - 'Environments: no source ties yttrium metal to a named space environment, so no tags.environments are set.'
  - Vapour pressure, heat of fusion and ionisation energies are in the Wikipedia infobox and PubChem but are not in the property canon, so they are left out.
  - Electronegativity (Pauling 1.22) is in the Wikipedia infobox but has no canonical name in the property file, so it is left out.
  - Oxidation rate of yttrium in air at high temperature (beyond the 750 °C water-vapour film result) was not found in an opened source.
  - Cold welding, outgassing and atomic oxygen erosion of yttrium in vacuum were not found in the sources read.
  - 'Process: the fluoride calcium reduction comes from PubChem. No primary process reference was opened.'
  - American Elements (HTTP 403 or a bot check) and VWR (bot check) yttrium pages could not be read.
  - The Goodfellow yttrium product page returned 404 and was not read.
sources:
  usgs-y:
    title: 'Mineral Commodity Summaries 2026: Yttrium (USGS)'
    id: USGS MCS 2026, February 2026, prepared by Shelby N. Johnston
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-yttrium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  pubchem-y:
    title: 'PubChem compound record: Yttrium (CID 23993), including ECHA C&L Inventory classification'
    id: CID 23993; CAS 7440-65-5
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23993
    year: 2026
    kind: database
    license: public domain (NCBI)
  wiki-y:
    title: Yttrium (Wikipedia)
    url: https://en.wikipedia.org/wiki/Yttrium
    year: 2026
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  sam-powder-sds:
    title: 'Safety Data Sheet: Yttrium Powder (Stanford Advanced Materials, revised 2023-08-01)'
    id: CAS 7440-65-5
    url: https://samaterials.com/tds/1697121527-1311-yttrium-powder-y-powder-spherical-sds.pdf
    year: 2023
    kind: datasheet
    license: supplier safety data sheet, cited not reproduced
  sam-y40-sds:
    title: 'Safety Data Sheet: Yttrium, powder, -40 mesh, 99.5% trace rare earth metals basis (Stanford Advanced Materials, version 3.0)'
    id: CAS 7440-65-5
    url: https://samaterials.com/tds/1711612168-YM1089-Yttrium-Metal-Powder-(Y-Metal-Powder)-sds.pdf
    year: 2017
    kind: datasheet
    license: supplier safety data sheet, cited not reproduced
  materion-y-sds:
    title: 'Safety Data Sheet: Yttrium metal (Materion Advanced Chemicals, SDS Y-MSDS0013, issue 2015-12-16)'
    id: SDS Y-MSDS0013
    url: https://www.physics.purdue.edu/primelab/safety/MSDS/SDS/yttriem%20metal%20%20-%20Materion.pdf
    year: 2015
    kind: datasheet
    license: supplier safety data sheet, cited not reproduced
  apollo-y-sds:
    title: 'Safety Data Sheet: Yttrium, powder -40 mesh (Apollo Scientific, part IN3826, issue 2022)'
    id: IN3826; CAS 7440-65-5
    url: https://store.apolloscientific.co.uk/storage/msds/IN3826_msds.pdf
    year: 2022
    kind: datasheet
    license: supplier safety data sheet, cited not reproduced
  luxfer-we43b:
    title: Elektron WE43B magnesium casting alloy (Luxfer MEL Technologies product page)
    id: UNS M18430; AMS 4427
    url: https://www.luxfermeltechnologies.com/elektron-we43b/
    kind: datasheet
    license: supplier web page, cited not reproduced
  usgs-crit2025:
    title: About the 2025 List of Critical Minerals (USGS)
    id: Final 2025 List of Critical Minerals
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
    kind: web
    license: public domain (USGS)
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 14
  unreachable: 3
  caveats: 5
  note: 'Read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry. Unreachable or blocked: American Elements and VWR yttrium pages (bot checks), Goodfellow yttrium page (404). Caveats: most physical values come from one encyclopedia infobox and are single-source; the critical-mineral listing was read through a fetch summary; the boiling point and melting point differ between sources; the hazard classification of the powder differs between suppliers; the supply shares are U.S. import shares, not world production.'
story:
  recipe:
    line: Yttrium is a single-element metal (Y) with a hexagonal close-packed structure at room temperature (Wikipedia). It is made by reduction of its fluoride with calcium (PubChem). Most of it is recovered from rare-earth minerals with the other lanthanides, and pure yttrium can be obtained by ion-exchange separation of the oxide (Wikipedia).
    parts:
      - name: Yttrium
        symbol: 'Y'
        atoms: 1
        atomic_weight: 88.906
        role: The whole material. Wikipedia prints the abridged standard atomic weight of 88.906; the commercial powder is 99.5 % or more yttrium, with trace rare earths (Stanford 40-mesh SDS).
  risk_groups:
    - title: For people
      level: 1
      verdict: Form-dependent
      lead: The hazard is in the fine form. Bulk metal is stable in air, but powder, shavings and turnings can catch fire, and the suppliers disagree on how they are classified.
      points:
        - label: Powder and turnings
          line: The 40-mesh powder SDS from Stanford Advanced Materials and the Apollo SDS classify the powder as pyrophoric (H250) and flammable (H228). The Materion SDS classifies yttrium metal only as a flammable solid of Category 2.
        - label: Dust and fume
          line: The OSHA and ACGIH limit is 1 mg/m3 as Y. The NIOSH guidance is a respirator with an N95, R95 or P95 filter up to 10 mg/m3 (PubChem).
        - label: Toxicity
          line: The 40-mesh powder SDS gives H302, H312 and H332 (harmful if swallowed, in contact with skin or if inhaled), and the ECHA notifications include H371 for lung effects. PubChem notes that most ECHA reports do not meet GHS criteria.
    - title: If it fails
      lead: 'The sources give three failure routes: a fire in fines, a reaction with water that releases hydrogen, and nitride formation at high temperature.'
      points:
        - label: Fire in fines
          line: Shavings or turnings can ignite in air above 400 °C (Wikipedia, citing CRC). The Stanford 40-mesh powder SDS classifies the powder as pyrophoric.
        - label: Water
          line: PubChem says yttrium reacts with water to form hydrogen. The Stanford 40-mesh SDS says it reacts violently with water, and the Apollo SDS says contact releases flammable gases.
        - label: Nitrogen at high temperature
          line: Heating to 1000 °C in nitrogen forms yttrium nitride (Wikipedia).
    - title: Handling and storage
      points:
        - label: Keep it dry and sealed
          line: Store under a dry inert gas, away from air and water, in a tightly sealed container in a cool, dry place (Stanford SDS, Section 7).
        - label: Fire
          line: Use a special powder for metal fires, dry sand or a dry sodium-chloride based extinguisher. Do not use water (Apollo and Stanford SDSs). Materion lists water fog as an option, so check the SDS for your supplier.
  why: Yttrium is a rare-earth metal, chemically closer to the lanthanides than to its neighbour scandium. It is used mostly for what its oxide and garnet forms do, not for the metal itself. Yttrium phosphors make white LEDs and the red of colour screens, and yttrium-aluminium-garnet crystals make solid-state laser rods. As a metal it adds strength and oxidation resistance to some magnesium and aluminium alloys, and WE43B uses about 4 % yttrium for hot aerospace castings.
  uses:
    - where: LED and display phosphors
      line: Wikipedia says the most important present-day use of yttrium is as a component of phosphors, especially those used in LEDs. Yttrium-based phosphors also gave the red colour in older television tubes.
    - where: Solid-state lasers
      line: USGS says yttrium-aluminum-garnet crystals are used in lasers for communication, industrial and medical applications.
    - where: Magnesium alloy castings
      line: The WE43B casting alloy contains yttrium at 3.7 to 4.3 % (Luxfer). Luxfer says its high-temperature retention is of interest to designers of aero-engines, helicopter transmissions, missiles and high-performance cars.
  can_do:
    - label: Density
      value: 4.469 g/cm3
      benchmark: density
      line: The density is 4.469 g/cm3 at 20 °C (Wikipedia), and the powder SDS prints 4.47 g/cm3 at 20 °C.
    - label: Melting
      value: 1526 °C
      benchmark: melting_point
      line: The melting point is 1526 °C (Wikipedia). The powder SDS prints 1522 °C.
    - label: Heat
      value: 17.2 W/(m·K)
      benchmark: thermal_conductivity
      line: The thermal conductivity is 17.2 W/(m·K) (Wikipedia). The temperature is not stated in the infobox.
    - label: Stiffness
      value: 63.5 GPa
      benchmark: elastic_modulus
      line: Young's modulus is 63.5 GPa, shear modulus 25.6 GPa and Poisson's ratio 0.243 (Wikipedia infobox).
  compare: 'Yttrium''s main strength is not the metal itself: it is the oxide, the garnet and the phosphor forms that make it useful. The metal is soft and reactive when finely divided, and its supply is concentrated in China. The compare rows give yttrium''s own values only, because this profile does not carry the other metals as sources.'
  compare_rows:
    - label: Density
      benchmark: density
    - label: Melting point
      benchmark: melting_point
    - label: Thermal conductivity
      benchmark: thermal_conductivity
  handling:
    - Keep yttrium powder and turnings dry and sealed under dry inert gas, away from air and water (Stanford SDS).
    - Use a special powder, dry sand or a dry salt-based extinguisher for metal fires, and do not use water (Apollo, Stanford).
    - Use respiratory protection where dust forms, and keep exposure at or below 1 mg/m3 as Y (OSHA).
    - Ground and bond containers and use explosion-proof equipment when handling the powder (Stanford 40-mesh SDS).
  good_for:
    - 'Phosphors: yttrium is in the phosphors of white LEDs and of colour screens (Wikipedia, USGS).'
    - 'Solid-state lasers: YAG crystals are used in communication, industrial and medical lasers (USGS).'
    - 'Hot magnesium castings: WE43B with about 4 % yttrium is for aero-engine and racing parts (Luxfer).'
  watch_out:
    - Fine powder and turnings ignite in air, and the 40-mesh powder is classed as pyrophoric (Stanford, Apollo).
    - Yttrium reacts with water to release hydrogen (PubChem, Apollo).
    - The United States imports almost all of its yttrium metal and compounds, 70 % from China in 2021 to 2024 (USGS).
    - The suppliers' hazard classifications differ, so check the SDS for the exact product.
  verdict: Yttrium is a rare-earth metal whose main value lies in its phosphor and laser-crystal forms and in small alloy additions. Its density of 4.469 g/cm3 and melting point of 1526 °C are well documented, but most of the physical values are single-source, and fine powder is pyrophoric. The United States imports almost all its supply, and China is the main source.