spore: profile
id: bismuth-ferrite
spore_version: 0.2
family: oxide-ceramics
name: Bismuth ferrite
abbreviation: BFO
role: multiferroic perovskite oxide (ferroelectric and antiferromagnetic at room temperature)
category: ceramics
type: oxides
summary: |
  Bismuth ferrite (BiFeO3, BFO) is a perovskite oxide that is both ferroelectric and antiferromagnetic at room temperature. A 2020 open-access review gives its ferroelectric Curie temperature as 1103 K and its antiferromagnetic Neel temperature as 643 K. A supplier lists a density of 8.22 g/cm3 for the powder, and the one safety data sheet we read lists no hazard statements.
best_for: Research into room-temperature multiferroic devices, such as ferroelectric memory and ferroelectric photovoltaic test structures
weakest_at: 'Hard to make as a single phase: secondary phases and oxygen vacancies raise leakage current, and the hazard and thermal data are thin'
identity:
  formula: BiFeO3
  cas: 12010-42-3
  crystal_system: rhombohedral
  space_group: R3c
  designations:
    - system: Trade name
      code: Bismuth iron oxide
      source: samaterials-sds
      where: Section 1, Trade Name
  source: alfa-bfo
  where: 'Product page: CAS number 12010-42-3 and molecular formula BiFeO3; rhombohedral R3c structure from pmc-bfo-review, Crystal Structure of BFO section'
tags:
  environments: []
  stresses: []
  applications: []
properties:
  - benchmark: curie_temperature
    label: Ferroelectric Curie temperature
    value: 1103
    unit: K
    scope: material
    conditions:
      basis: bulk ferroelectric phase transition, as quoted in the review together with its cited work
      form: not stated in the review
    method: Value stated in an open-access review (it cites earlier work for it)
    status: ground
    note: Wikipedia (fetched in this run) gives approximately 1100K for the same transition; the review's 1103 K is recorded here.
    source: pmc-bfo-review
    where: Text in the crystal structure section, quoted as 'Curie temperature (TC) of 1103 K'
  - benchmark: neel_temperature
    label: Antiferromagnetic Neel temperature (G-type)
    value: 643
    unit: K
    scope: material
    conditions:
      basis: G-type antiferromagnetic transition, as quoted in the review together with its cited work
    method: Value stated in an open-access review (it cites earlier work for it)
    status: ground
    note: Wikipedia (fetched in this run) gives approximately 653 K; the review's 643 K is recorded here. The two differ by 10 K.
    source: pmc-bfo-review
    where: Text in the crystal structure section, quoted as 'Neel temperature (T N) of 643 K'
  - benchmark: lattice_constant_a
    label: Lattice constant a, ceramic bulk (rhombohedral setting in the review)
    value: 5.63
    unit: Å
    scope: material
    conditions:
      form: ceramic bulk
      temperature: room temperature
      space_group: R3c
      angle_in_same_sentence: 89.45 degrees
    method: Value stated in an open-access review
    status: ground
    note: Arxiv Table 1 gives a different experimental setting (a = 5.64 A with alpha = 59.42 deg), so the two cell descriptions are not interchangeable.
    source: pmc-bfo-review
    where: Text in the crystal structure section, quoted as 'lattice constant of a = 5.63 A'
  - benchmark: rhombohedral_angle
    label: Rhombohedral angle, ceramic bulk
    value: 89.45
    unit: °
    scope: material
    conditions:
      form: ceramic bulk
      temperature: room temperature
      space_group: R3c
    method: Value stated in an open-access review
    status: ground
    source: pmc-bfo-review
    where: Text in the crystal structure section, quoted as 'rhombohedral angle of 89.45°'
  - benchmark: lattice_constant_a
    label: Lattice constant a, experimental (Table 1 of the 2022 paper)
    value: 5.64
    unit: Å
    scope: material
    conditions:
      state: pure BiFeO3, R3c phase
      temperature: ambient temperature (as the table states)
      cell_setting: rhombohedral, with alpha 59.42 deg
    method: Experimental value printed in a table of a 2022 arXiv paper, which cites an earlier source for it
    status: ground
    source: arxiv-2201.11161
    where: Table 1, row a/Å, Expt. column
  - benchmark: rhombohedral_angle
    label: Rhombohedral angle, experimental (Table 1 of the 2022 paper)
    value: 59.42
    unit: deg
    scope: material
    conditions:
      state: pure BiFeO3, R3c phase
      temperature: ambient temperature (as the table states)
      cell_setting: rhombohedral
    method: Experimental value printed in a table of a 2022 arXiv paper, which cites an earlier source for it
    status: ground
    source: arxiv-2201.11161
    where: Table 1, row alpha/deg, Expt. column
  - benchmark: band_gap
    label: Band gap, thin films (experimental range)
    value: 2.6
    value_high: 2.8
    bound: range
    unit: eV
    scope: material
    conditions:
      form: thin films
      temperature: ambient, as quoted
    method: Range quoted in a 2022 arXiv paper, which cites an earlier source; the paper says 'most commonly reported values for thin films range between 2.6 and 2.8 eV'
    status: ground
    note: The same paper gives 2.66 eV for pure BiFeO3 from another study (Peng et al.) without a stated test condition; that value is not recorded here.
    source: arxiv-2201.11161
    where: Introduction, paragraph on band gap; Table 1, row Eg/eV, Expt. column
  - benchmark: remanent_polarization
    label: Remnant ferroelectric polarization, thin film
    value: 55
    unit: µC/cm2
    scope: material
    conditions:
      form: thin film
      note: approximate value, printed with a tilde in the review
    method: Approximate value quoted in an open-access review, for the first BFO thin film it discusses
    status: ground
    source: pmc-bfo-review
    where: Text on thin-film polarization, quoted as 'remnant ferroelectric polarization of Pr ~ 55 µC cm-2'
  - benchmark: remanent_polarization
    label: Polarization along [111], bulk ceramic at 77 K
    value: 6.1
    unit: µC/cm2
    scope: material
    conditions:
      form: bulk ceramic
      temperature: 77 K
      direction: '[111]'
    method: Value quoted in an open-access review for a measurement it dates to the 1970s
    status: ground
    source: pmc-bfo-review
    where: Text on ferroelectric hysteresis of BFO ceramic bulk, quoted as 'polarization value to be 6.1 µC cm-2 along the [111] direction at 77 K'
  - benchmark: spin_cycloid_period
    label: Spin cycloid period along [111]
    value: 62
    value_high: 64
    bound: range
    unit: nm
    scope: material
    conditions:
      direction: '[111]'
      temperature: not stated in the review
    method: Range quoted in an open-access review for the long-period spin cycloid of the G-type order
    status: ground
    source: pmc-bfo-review
    where: Text on the G-type antiferromagnetic spin cycloid, quoted as '62-64 nm along the [111] direction'
  - benchmark: density
    label: Density, powder (supplier listing)
    value: 8.22
    unit: g/cm3
    scope: material
    conditions:
      form: crystalline powder, as listed by the supplier
      purity: 99.9%
    method: Supplier product page listing, printed as '8.22 g/cm3'; no measurement method given
    status: ground
    note: The Stanford Advanced Materials sheet for the same product prints Density as N/A, so this value comes from one supplier page only.
    source: samaterials-bfo
    where: Product specification table, Density row
  - benchmark: density
    label: Density, powder (second supplier listing)
    value: 8.22
    unit: g/cm3
    scope: material
    conditions:
      form: powder, as listed by the supplier
      product: CAS 12010-42-3
    method: Supplier product page listing, printed as '8.22 g/cm3'; no measurement method given
    status: ground
    source: alfa-bfo
    where: Product properties list, Density
  - benchmark: melting_point
    label: Melting point, powder (supplier listing)
    value: 1255
    unit: °C
    scope: material
    conditions:
      form: powder, as listed by the supplier
    method: Supplier product page listing; the review and the 2022 paper print no melting point
    status: ground
    source: samaterials-bfo
    where: Product specification table, Melting Point row
  - benchmark: melting_point
    label: Melting point, powder (second supplier listing)
    value: 1255
    unit: °C
    scope: material
    conditions:
      form: powder, as listed by the supplier
    method: Supplier product page listing; no measurement method given
    status: ground
    source: alfa-bfo
    where: Product properties list, Melting point
  - benchmark: molar_mass
    label: Molar mass (PubChem computed)
    value: 312.82
    unit: g/mol
    scope: material
    conditions:
      basis: computed by PubChem from the molecular formula BiFeO3
    method: Computed value in the PubChem compound record (PubChem release 2025.09.15)
    status: calculated
    note: The Stanford Advanced Materials sheet prints a molecular weight of 321.83 g/mol for the same product, which conflicts with this value; both are recorded in the story.
    source: pubchem-bfo
    where: Molecular Weight section of the compound record
corrosion:
  - environment: Oxidizing agents and air (supplier safety data sheet)
    headline: The supplier sheet lists oxidizing agents as reactive partners and gives no corrosion test.
    effect: The sheet states the product is stable under recommended storage conditions, reacts with oxidizing agents, and gives metal oxide fume as its hazardous decomposition product. No corrosion, humidity or ageing test for bismuth ferrite was found in the sources we hold.
    rating: unknown
    conditions:
      exposure: supplier storage and reactivity statements
      test: none found
    source: samaterials-sds
    where: Section 10, Reactivity
risks:
  hazards:
    - text: 'The Stanford Advanced Materials sheet for catalogue BI6032 (bismuth iron oxide, BiFeO3) prints Signal Word: None, Hazard Statements: None and Precautionary Statements: None. Its HMIS ratings are health 1, flammability 0 and physical 1.'
      ghs: []
      source: samaterials-sds
      where: Section 2, Hazards Identification
    - text: 'The same sheet prints ''Median Lethal Dose: 4000 mg/kg for rat by mouth'' and ''Potential Health Effects: May cause irritation'' for eyes, skin, ingestion and inhalation.'
      ghs: []
      source: samaterials-sds
      where: Section 11, Toxicological Information
    - text: PubChem's compound record for bismuth ferrite (CID 161118030) has no GHS classification section, so PubChem gives no GHS classification for this compound.
      ghs: []
      source: pubchem-bfo
      where: Compound record, list of sections (no Safety and Hazards section)
  failure_risks:
    - mode: Oxygen vacancies and secondary phases
      trigger: Volatile bismuth and a changing iron valence during sintering or film growth
      consequence: Sharply higher leakage current and difficulty obtaining a saturated ferroelectric hysteresis loop at room temperature.
      severity: moderate
      source: pmc-bfo-review
      where: Text on leakage current and secondary phases
  side_effects: []
  handling:
    - text: Handle under dry protective gas and wash thoroughly after handling. Store in a cool dry place in a tightly sealed container under dry inert gas.
      source: samaterials-sds
      where: Section 7, Handling and Storage
    - text: 'The sheet prints ''Threshold Limit Value: 1 mg/m3 as Fe, long-term value'' and recommends a dust respirator, rubber gloves, and safety glasses or goggles.'
      source: samaterials-sds
      where: Section 8, Exposure Controls and Personal Protection
    - text: For spills, the sheet advises a HEPA filter vacuum and says to take care not to raise dust.
      source: samaterials-sds
      where: Section 6, Accidental Release Measures
  mitigations:
    - text: Ion substitution and solid solutions with other perovskite oxides are the most effective methods to suppress high leakage current, according to the review.
      source: pmc-bfo-review
      where: Text on leakage current, ion substitution
uses:
  - application: electronics-and-chips
    device: Nonvolatile ferroelectric memory (research prototypes)
    example: The review says BFO-based nanomaterials have both ferroelectricity and ferromagnetism at room temperature, which gives them great potential in high-density ferroelectric devices such as nonvolatile memories.
    source: pmc-bfo-review
    where: Section For Electronics
  - application: electronics-and-chips
    device: Ferroelectric photovoltaic devices (research)
    example: The review says the photovoltaic effect of ferroelectric nanomaterials depends on domain structure, polarization direction and band gap, and that BFO is studied for it.
    source: pmc-bfo-review
    where: Text on the photovoltaic effect of ferroelectric nanomaterials
supply:
  - subject: Bismuth
    abundance: Rarely mined as a primary product. Bismuth is mostly a byproduct of lead ore processing, and the USGS estimates world production at 16,000 tons in 2025.
    producers:
      - country: China
        share_percent: 88
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals
        listed: true
    recycling: 'USGS: recycled bismuth-containing alloy scrap was estimated to compose up to 10% of U.S. bismuth apparent consumption for 2021 to 2025.'
    substitutes:
      - 'USGS: bismuth compounds can be replaced in pharmaceutical applications by alumina, antibiotics, calcium carbonate and magnesia. The chapter does not discuss ferroelectric oxides.'
    source: usgs-mcs2026-bismuth
    where: Events, Trends and Issues; World Refinery Production and Capacity table (2025, China 88% of world production); Recycling; Substitutes
media: []
documents:
  - title: 'Safety Data Sheet: Bismuth Iron Oxide (Stanford Advanced Materials, catalogue BI6032)'
    type: sds
    url: https://www.samaterials.com/tds/sc/1752820091-BI6032.pdf
    year: 2015
  - title: 'PubChem compound record: Bismuth ferrite (CID 161118030)'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/161118030
    year: 2025
  - title: Structure, Performance, and Application of BiFeO3 Nanomaterials (open access)
    type: paper
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC7770668/
    year: 2020
  - title: 'Co-substituted BiFeO3: electronic, ferroelectric, and thermodynamic properties from first principles (arXiv)'
    type: paper
    url: https://arxiv.org/pdf/2201.11161
    year: 2022
  - title: 'Mineral Commodity Summaries 2026: Bismuth (USGS)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-bismuth.pdf
    year: 2026
gaps:
  - No flight, vacuum, radiation, thermal-vacuum or other space-environment result for bismuth ferrite was found, so the environments and applications tags are empty.
  - The density and melting point come only from two supplier product pages. The Stanford Advanced Materials sheet prints Density and Melting Point as N/A, and no peer-reviewed density or melting point was found in the sources we hold.
  - 'The molecular weight conflicts: PubChem computes 312.82 g/mol, while the Stanford Advanced Materials sheet prints 321.83 g/mol. Both are recorded in the story.'
  - The safety data sheet prints CAS as NIL, while the supplier product pages, Wikipedia and PubChem name CAS 12010-42-3. The CAS number is taken from the product page.
  - PubChem gives no GHS classification for this compound. Only one supplier safety data sheet was read, and it lists no hazard statements.
  - The band gap value comes from a 2022 first-principles paper that quotes earlier experiments; no primary measurement paper was read.
  - The two lattice descriptions use different cell settings (a of 5.63 A with 89.45 deg in the review, and a of 5.64 A with alpha of 59.42 deg in the 2022 paper). Both are recorded.
  - The Neel and Curie temperatures differ slightly between the review (643 K and 1103 K) and Wikipedia (approximately 653 K and approximately 1100K). The review's values are recorded and the difference is noted on each row.
  - No corrosion, humidity, ageing or chemical-resistance test for bismuth ferrite was found in the sources we hold.
  - The EU critical raw materials list status of bismuth was not checked in this run.
  - No designation such as UNS, EN or ASTM applies to this oxide. The only other name is the supplier trade name Bismuth iron oxide from the safety data sheet.
  - Atomic weights are left out of the recipe because no fetched source prints them for each element.
  - The uses are research devices described in a review. No device performance number for a memory or photovoltaic device was found in the sources we hold.
  - 'Several properties use short snake_case benchmark names that are not in the canonical list: lattice_constant_a, rhombohedral_angle, neel_temperature, band_gap, remanent_polarization, spin_cycloid_period and molar_mass.'
sources:
  pmc-bfo-review:
    title: Structure, Performance, and Application of BiFeO3 Nanomaterials
    id: Nano-Micro Lett. 2020 Mar 28;12:81 (PMC7770668)
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC7770668/
    year: 2020
    kind: paper
    license: open access on PMC; licence not checked
  samaterials-bfo:
    title: Bismuth ferrite (BiFeO3) powder, catalogue BI6032, Stanford Advanced Materials product page
    id: catalogue BI6032; CAS 12010-42-3
    url: https://powder.samaterials.com/bi6032-bismuth-ferrite-powder.html
    kind: datasheet
    license: supplier web page, cited not reproduced
  alfa-bfo:
    title: Bismuth Ferrite, CAS 12010-42-3, Alfa Chemistry nanomaterials product page
    id: catalogue ACM12010423; CAS 12010-42-3
    url: https://nanomaterials.alfa-chemistry.com/product/bismuth-ferrite-cas-12010-42-3-306117.html
    kind: web
    license: supplier web page, cited not reproduced
  samaterials-sds:
    title: 'Safety Data Sheet: Bismuth Iron Oxide (Stanford Advanced Materials, catalogue BI6032), last revised 07/08/2015'
    id: catalogue BI6032
    url: https://www.samaterials.com/tds/sc/1752820091-BI6032.pdf
    year: 2015
    kind: datasheet
    license: supplier document, cited not reproduced
  pubchem-bfo:
    title: PubChem compound record, Bismuth ferrite (CID 161118030), PUG-View JSON
    id: CID 161118030
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/161118030/JSON
    year: 2025
    kind: database
    license: public domain (NCBI)
  arxiv-2201.11161:
    title: 'Co-substituted BiFeO3: electronic, ferroelectric, and thermodynamic properties from first principles'
    id: arXiv:2201.11161
    url: https://arxiv.org/pdf/2201.11161
    year: 2022
    kind: paper
    license: arXiv preprint, licence not checked
  usgs-mcs2026-bismuth:
    title: 'Mineral Commodity Summaries 2026: Bismuth'
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-bismuth.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-crit2025:
    title: About the 2025 List of Critical Minerals (USGS)
    id: Final 2025 List of Critical Minerals, November 2025
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
    kind: web
    license: public domain (USGS)
  wikipedia-bfo:
    title: Bismuth ferrite, Wikipedia (used for the CAS number, the abbreviation and the note on Neel and Curie temperatures only)
    url: https://en.wikipedia.org/wiki/Bismuth_ferrite
    kind: web
    license: Wikipedia text, CC BY-SA (licence not re-checked in this run)
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 15
  unreachable: 0
  caveats: 2
  note: Values read in this run from the sources listed. The lattice and Neel and Curie values differ slightly between sources, so each is recorded with its own source and cell setting.
story:
  recipe:
    line: Bismuth ferrite is a perovskite oxide with the formula BiFeO3, which holds one bismuth atom, one iron atom and three oxygen atoms per formula unit. The supplier lists it as a crystalline perovskite powder, and the review gives its room-temperature structure as rhombohedral in space group R3c.
    parts:
      - name: Bismuth
        symbol: Bi
        role: Sits on the large cation site. Its lone pair of electrons shifts the bismuth ion off centre, which creates the ferroelectric polarization along the [111] direction, per the review.
      - name: Iron
        symbol: Fe
        role: Sits on the smaller cation site. Its magnetic moments order antiferromagnetically in a G-type pattern below the Neel temperature.
      - name: Oxygen
        symbol: O
        role: Forms the oxygen octahedra around the iron, which hold the framework together and respond to the bismuth shift.
  why: Bismuth ferrite (BiFeO3, BFO) is a perovskite oxide that is ferroelectric and antiferromagnetic at room temperature, which makes it a multiferroic. An open-access review gives its ferroelectric Curie temperature as 1103 K and its antiferromagnetic Neel temperature as 643 K, both far above room temperature. The material is studied for nonvolatile memory and ferroelectric photovoltaic devices, and most of the work so far is in films and ceramics rather than in finished products.
  uses:
    - where: Nonvolatile memory research
      line: The review says BFO-based nanomaterials show ferroelectricity and ferromagnetism at room temperature, which gives them potential in high-density ferroelectric devices such as nonvolatile memories. This is a research direction, not a product.
    - where: Ferroelectric photovoltaic research
      line: The review says the photovoltaic effect of ferroelectric nanomaterials depends on domain structure, polarization direction and band gap. A 2022 paper gives a thin-film band gap of 2.6 to 2.8 eV.
  can_do:
    - label: Ferroelectric transition
      benchmark: curie_temperature
      line: The ferroelectric Curie temperature is 1103 K, according to the review. That is far above room temperature.
    - label: Magnetic order
      benchmark: neel_temperature
      line: The Neel temperature is 643 K. Below it the iron moments order in a G-type antiferromagnetic pattern with weak magnetization from canting.
    - label: Polarization
      value: About 55 µC/cm2 in a thin film; 6.1 µC/cm2 along [111] in a bulk ceramic at 77 K
      line: The review quotes a remnant polarization of about 55 µC/cm2 for a thin film. For a bulk ceramic it quotes 6.1 µC/cm2 along [111] at 77 K, a value from a 1970s measurement.
    - label: Band gap
      value: 2.6 to 2.8 eV for thin films
      line: Thin films have a band gap of 2.6 to 2.8 eV, the range most often reported according to a 2022 paper that cites earlier experiments.
    - label: Density
      value: 8.22 g/cm3 for the powder (supplier)
      line: A supplier lists a density of 8.22 g/cm3 for its powder. This is a listed value, and the second safety data sheet gives no density.
  compare: The sources we hold do not compare bismuth ferrite with other materials directly, so this profile compares the figures for this material only. Its transition temperatures sit far above room temperature (Curie 1103 K, Neel 643 K), and its thin-film band gap is 2.6 to 2.8 eV. Its density of 8.22 g/cm3 and melting point of 1255 °C come from supplier pages, and the molecular weight conflicts, at 312.82 g/mol from PubChem against 321.83 g/mol from the supplier sheet.
  compare_rows:
    - label: Ferroelectric Curie temperature
      benchmark: curie_temperature
    - label: Antiferromagnetic Neel temperature
      benchmark: neel_temperature
    - label: Density (powder, supplier)
      benchmark: density
  handling:
    - Handle under dry protective gas and wash thoroughly after handling, according to the supplier sheet.
    - Store in a cool dry place in a tightly sealed container under dry inert gas, apart from oxidizing agents.
    - Wear a dust respirator, rubber gloves, and safety glasses or goggles, and avoid raising dust.
    - For spills, use a HEPA filter vacuum.
  good_for:
    - Research into ferroelectric memory and photovoltaic test devices, where room-temperature multiferroic behaviour is the point.
    - 'High transition temperatures: the Curie temperature is 1103 K and the Neel temperature is 643 K.'
  watch_out:
    - Secondary phases and oxygen vacancies make single-phase material hard to prepare, and they raise leakage current.
    - 'Thin-film and bulk values differ: the remnant polarization is about 55 µC/cm2 in a thin film, but 6.1 µC/cm2 in a bulk ceramic at 77 K.'
    - The molecular weight conflicts (312.82 g/mol from PubChem, 321.83 g/mol from the supplier sheet), and the density and melting point come only from supplier pages.
  risk_groups:
    - title: For people
      level: 1
      verdict: Irritant per the SDS; no GHS classification found
      lead: The one safety data sheet found lists no hazard statements and says the material may cause irritation. Treat the powder as an irritant and keep dust down.
      points:
        - label: Classification
          line: The supplier sheet prints no signal word and no hazard statements. PubChem's record for the compound has no GHS classification section.
        - label: Toxicity
          line: The sheet gives a median lethal dose of 4000 mg/kg for rat by mouth, and says the powder may cause irritation to eyes, skin, the stomach and the airways.
        - label: Dust
          line: Avoid raising dust. The sheet gives a threshold limit value of 1 mg/m3 as Fe (long-term value) and recommends a dust respirator, rubber gloves and safety glasses.
        - label: In a fire
          line: The sheet calls the material non-flammable and says decomposition gives metal oxide fume.
    - title: Chemical reactions
      lead: The sheet lists oxidizing agents as reactive partners.
      points:
        - label: Keep apart
          line: Store apart from oxidizing agents, under dry inert gas, as the supplier's storage and reactivity sections advise.
  verdict: Bismuth ferrite is a research material with transition temperatures far above room temperature. Its one supplier safety data sheet lists no hazard statements, and no space data were found.