spore: profile
id: nimnga-shape-memory
spore_version: 0.2
family: nickel-manganese-gallium-heusler
name: Nickel-manganese-gallium magnetic shape-memory alloy
abbreviation: Ni-Mn-Ga
role: magnetic shape-memory alloy for actuators and magnetocaloric cooling
category: metals
type: shape-memory-alloys
summary: |
  Ni-Mn-Ga is a Heusler alloy of nickel, manganese and gallium, with stoichiometric Ni2MnGa as its reference composition. Unlike nitinol, which changes shape on heating, its martensite can be reoriented by a magnetic field. Single crystals of Ni48 Mn31 Ga21, Ni49.8 Mn28.5 Ga21.7 and Ni48.2 Mn30.8 Ga21 gave 5.1, 6.0 and 7.3 % magnetically induced strain in one review table. The Curie temperature of stoichiometric Ni2MnGa is about 370 K, and the martensitic transition temperature of the Ni2+xMn1-xGa series rises from 201 K at x = 0 to 342 K at x = 0.19.
best_for: Single-crystal actuators that must move by a magnetic field rather than by heating, with 5.1 to 7.3 % magnetically induced strain in the review table and a martensite that is magnetically controlled
weakest_at: Brittleness and a low martensitic transformation temperature. A 2000 MRS-J paper names both as the main obstacles to practical use, and strain is lost when the crystal is cut from the middle of the boule
identity:
  formula: Ni2MnGa, stoichiometric Heusler alloy; the studied series is Ni2+xMn1-xGa with x from 0 to 0.19
  source: khovailo2004
  where: Abstract and composition formula Ni2+xMn1-xGa, 0 to 0.19; Ni2MnGa at x = 0 (introduction)
  designations: []
tags:
  environments: []
  stresses: []
  applications:
    - mechanisms
    - thermal-control
properties:
  - benchmark: curie_temperature
    label: Curie temperature, stoichiometric Ni2MnGa
    value: 370
    unit: K
    scope: material
    conditions:
      composition: Ni2MnGa, x = 0
      note: printed as about 370 K
    method: Value stated in the text on the composition dependence of TC, from magnetization measurements reported in the paper
    status: ground
    source: khovailo2004
    where: Text on composition dependence, sentence beginning The Curie temperature TC is about 370 K in stoichiometric composition
  - benchmark: martensitic_transition_temperature
    label: Martensitic transition temperature Tm, x = 0 (Ni2MnGa)
    value: 201
    unit: K
    scope: material
    conditions:
      composition: Ni2+xMn1-xGa, x = 0
    method: Tm column of Table I in the paper, which gives the transition temperature for each composition
    status: ground
    source: khovailo2004
    where: Table I, Tm column, row x = 0
  - benchmark: martensitic_transition_temperature
    label: Martensitic transition temperature Tm, x = 0.04
    value: 237
    unit: K
    scope: material
    conditions:
      composition: Ni2+xMn1-xGa, x = 0.04
    method: Tm column of Table I in the paper
    status: ground
    source: khovailo2004
    where: Table I, Tm column, row x = 0.04
  - benchmark: martensitic_transition_temperature
    label: Martensitic transition temperature Tm, x = 0.08
    value: 265
    unit: K
    scope: material
    conditions:
      composition: Ni2+xMn1-xGa, x = 0.08
    method: Tm column of Table I in the paper
    status: ground
    source: khovailo2004
    where: Table I, Tm column, row x = 0.08
  - benchmark: martensitic_transition_temperature
    label: Martensitic transition temperature Tm, x = 0.12
    value: 294
    unit: K
    scope: material
    conditions:
      composition: Ni2+xMn1-xGa, x = 0.12
    method: Tm column of Table I in the paper
    status: ground
    source: khovailo2004
    where: Table I, Tm column, row x = 0.12
  - benchmark: martensitic_transition_temperature
    label: Martensitic transition temperature Tm, x = 0.16
    value: 315
    unit: K
    scope: material
    conditions:
      composition: Ni2+xMn1-xGa, x = 0.16
    method: Tm column of Table I in the paper
    status: ground
    source: khovailo2004
    where: Table I, Tm column, row x = 0.16
  - benchmark: martensitic_transition_temperature
    label: Martensitic transition temperature Tm, x = 0.19
    value: 342
    unit: K
    scope: material
    conditions:
      composition: Ni2+xMn1-xGa, x = 0.19
    method: Tm column of Table I in the paper; at x = 0.18 to 0.19 the Curie temperature merges with Tm
    status: ground
    source: khovailo2004
    where: Table I, Tm column, row x = 0.19
  - benchmark: latent_heat_martensitic_transition
    label: Latent heat of the martensitic transition, x = 0
    value: 270
    unit: J/mol
    scope: material
    conditions:
      composition: Ni2+xMn1-xGa, x = 0
    method: Q column of Table I in the paper, which the text links to the latent heat used in the Clapeyron-Clausius analysis
    status: ground
    source: khovailo2004
    where: Table I, Q column, row x = 0
  - benchmark: latent_heat_martensitic_transition
    label: Latent heat of the martensitic transition, x = 0.19
    value: 2260
    unit: J/mol
    scope: material
    conditions:
      composition: Ni2+xMn1-xGa, x = 0.19
    method: Q column of Table I in the paper
    status: ground
    source: khovailo2004
    where: Table I, Q column, row x = 0.19
  - benchmark: magnetic_field_induced_strain
    label: Magnetically induced strain, Ni48 Mn31 Ga21 single crystal
    value: 5.1
    unit: '%'
    scope: material
    conditions:
      composition: Ni48 Mn31 Ga21 (at.%), single crystal, single-variant martensite
      note: strain in the martensitic state set by variant reorientation in a magnetic field
    method: MFIS column of Table I in the review, which collects single-crystal values; the table lists references 74 and 135 for this row
    status: ground
    source: vasil2003
    where: Table I, Magnetically induced strains in Ni2+x+yMn1-xGa1-y alloys, row Ni48 Mn31 Ga21
  - benchmark: magnetic_field_induced_strain
    label: Magnetically induced strain, Ni49.8 Mn28.5 Ga21.7 single crystal
    value: 6
    unit: '%'
    scope: material
    conditions:
      composition: Ni49.8 Mn28.5 Ga21.7 (at.%), single crystal
    method: MFIS column of Table I in the review; the table cites reference 119 for this row
    status: ground
    source: vasil2003
    where: Table I, Magnetically induced strains, row Ni49.8 Mn28.5 Ga21.7
  - benchmark: magnetic_field_induced_strain
    label: Magnetically induced strain, Ni48.2 Mn30.8 Ga21 single crystal
    value: 7.3
    unit: '%'
    scope: material
    conditions:
      composition: Ni48.2 Mn30.8 Ga21 (at.%), single crystal
    method: MFIS column of Table I in the review; the table cites reference 81 for this row
    status: ground
    source: vasil2003
    where: Table I, Magnetically induced strains, row Ni48.2 Mn30.8 Ga21
  - benchmark: magnetic_field_induced_strain
    label: Magnetically induced strain, nonmodulated martensite single crystal
    value: 0.17
    unit: '%'
    scope: material
    conditions:
      composition: Ni53.1 Mn26.6 Ga20.3 (composition as printed, no at.% stated), single crystal, stress-free
      field: rotating magnetic field, strength not stated in the abstract
    method: Abstract value for a rotating field on a stress-free single crystal with nonmodulated martensite
    status: ground
    source: chernenko2009
    where: Abstract, first sentence
  - benchmark: martensitic_transition_temperature
    label: Martensitic transition temperature Ms, Ni48 Mn31 Ga21
    value: 301
    unit: K
    scope: material
    conditions:
      composition: Ni48 Mn31 Ga21 (at.%)
      note: Ms as printed in Table I of the review
    method: Ms column of Table I in the review, shown with the MFIS value for the same row
    status: ground
    source: vasil2003
    where: Table I, Ms column, row Ni48 Mn31 Ga21
  - benchmark: martensitic_transition_temperature
    label: Martensitic transition temperature Ms, Ni49.8 Mn28.5 Ga21.7
    value: 318
    unit: K
    scope: material
    conditions:
      composition: Ni49.8 Mn28.5 Ga21.7 (at.%)
      note: Ms as printed in Table I of the review
    method: Ms column of Table I in the review, shown with the MFIS value for the same row
    status: ground
    source: vasil2003
    where: Table I, Ms column, row Ni49.8 Mn28.5 Ga21.7
  - benchmark: magnetocrystalline_anisotropy_constant
    label: Uniaxial anisotropy constant Ku at room temperature, Ni48 Mn31 Ga21
    value: 1.7
    unit: 10^6 erg/cm3
    scope: material
    conditions:
      composition: Ni48 Mn31 Ga21 (at.%), single-variant state
      temperature: room temperature
      unit_in_source: 10^6 erg/cm3
    method: Ku value given in the review text for single-variant single crystals of this composition, and in the Ku column of Table I
    status: ground
    source: vasil2003
    where: Section on magnetocrystalline anisotropy, paragraph beginning with the values of Ku at room temperature
  - benchmark: magnetocrystalline_anisotropy_constant
    label: Uniaxial anisotropy constant Ku at room temperature, Ni48.2 Mn30.8 Ga21
    value: 2.13
    unit: 10^6 erg/cm3
    scope: material
    conditions:
      composition: Ni48.2 Mn30.8 Ga21 (at.%)
      unit_in_source: 10^6 erg/cm3
    method: Ku column of Table I in the review, with reference 81
    status: ground
    source: vasil2003
    where: Table I, Ku column, row Ni48.2 Mn30.8 Ga21
  - benchmark: magnetic_entropy_change
    label: Magnetic entropy change at the transition, field switched on
    value: 9
    unit: J/kgK
    scope: material
    conditions:
      composition: Ni-Mn-Ga alloy (composition not stated on the page)
      field: 26 kOe
      temperature: 338 K on turning the field on
    method: Largest entropy change in a 26 kOe field, as stated in the conference summary
    status: ground
    source: aliev2005
    where: Summary, first sentence on entropy changes
  - benchmark: magnetic_entropy_change
    label: Magnetic entropy change at the transition, field switched off
    value: 11
    unit: J/kgK
    scope: material
    conditions:
      composition: Ni-Mn-Ga alloy (composition not stated on the page)
      field: 26 kOe
      temperature: 344 K on turning the field off
    method: Largest entropy change in a 26 kOe field on field removal, as stated in the conference summary
    status: ground
    source: aliev2005
    where: Summary, second sentence on entropy changes
corrosion: []
risks:
  hazards:
    - text: 'Gallium, the Ga constituent: the supplier safety data sheet lists H290 (may be corrosive to metals) with signal word Warning, and P234, P390 and P406.'
      ghs:
        - H290
      source: sds-ga
      where: Section 2, hazard statements; precautionary statements
    - text: 'Nickel-based alloy SDS, the closest found for a nickel-rich alloy and not Ni-Mn-Ga itself: skin sensitisation Category 1 (H317), carcinogenicity Category 2 (H351), STOT repeated exposure Category 1 (H372) and aquatic chronic Category 1 (H410).'
      ghs:
        - H317
        - H351
        - H372
        - H410
      source: sds-ni-alloy
      where: Section 2.1, classification of the substance or mixture
  failure_risks:
    - mode: Brittleness
      trigger: Ni-Mn-Ga Heusler alloys processed for actuators
      consequence: The 2000 MRS-J paper calls inherent brittleness, together with lower martensitic transformation temperatures, a problem to be overcome before practical use.
      severity: high
      source: tsuchiya2000
      where: Introduction, first paragraph
    - mode: Loss of strain from sample position
      trigger: Single crystal cut from the middle of the boule instead of its beginning
      consequence: For samples cut from the middle of the single crystals no magnetically induced strain was observed, while a 6 % strain was seen in a sample cut from the beginning.
      severity: moderate
      source: vasil2003
      where: Section on magnetically induced strains, paragraph after Table I reference 141
    - mode: Composition shift of the transition
      trigger: Excess nickel, x in Ni2+xMn1-xGa, from 0 toward 0.19
      consequence: Tm rises from 201 K to 342 K and the Curie temperature falls toward the same value, so at x = 0.18 to 0.19 the alloy goes from paramagnetic austenite to martensite through a structural transition.
      severity: high
      source: khovailo2004
      where: Introduction and Table I
    - mode: No strain when the anisotropy is too weak
      trigger: Magnetocrystalline anisotropy energy below the effective elastic modulus of the twin boundaries
      consequence: Variant reorientation needs the anisotropy energy density to exceed the effective elastic modulus of the displacement of martensitic domain boundaries, so weaker anisotropy gives less strain.
      severity: moderate
      source: vasil2003
      where: Section on magnetically induced strains, paragraph beginning This occurs if the magnetocrystalline anisotropy energy density exceeds
  side_effects: []
  handling:
    - text: Melt the alloy in an argon arc, then homogenize the ingot at 1073 K for 48 to 72 hours in argon and quench into room-temperature water.
      source: tsuchiya2000
      where: Experimental section
    - text: Check composition by EDX after melting, because the transition temperature moves with the Ni, Mn and Ga content.
      source: tsuchiya2000
      where: Experimental section, composition analysis
    - text: Treat gallium as corrosive to metals (H290) and follow the supplier SDS for the alloy.
      source: sds-ga
      where: Section 2
  mitigations: []
uses:
  - application: mechanisms
    device: Magnetic actuators and magnetomechanical parts
    example: The 2000 MRS-J paper calls Ni-Mn-Ga a good candidate for magnetic actuator materials, because the alloy shows large twinning magnetostriction in its martensite phase.
    source: tsuchiya2000
    where: Introduction, first paragraph
  - application: thermal-control
    device: Magnetocaloric refrigerant
    example: A 2005 conference paper on Ni-Mn-Ga reports magnetic entropy changes of 9 J/kgK at 338 K and 11 J/kgK at 344 K in a 26 kOe field, the basis for magnetic refrigeration at room temperature.
    source: aliev2005
    where: Summary
story:
  risk_groups:
    - title: For people
      lead: Ni-Mn-Ga is a nickel alloy. The sources supplied here cover nickel-based alloy and gallium hazards, not a Ni-Mn-Ga supplier SDS.
      level: 2
      verdict: Nickel and gallium hazards
      points:
        - label: Codes found
          line: A nickel-based alloy SDS lists H317, H351, H372 and H410, and a gallium SDS lists H290, which may be corrosive to metals.
        - label: Gap
          line: No safety data sheet for the Ni-Mn-Ga alloy itself was read in this run, so the codes above are a proxy.
    - title: If it fails
      lead: The sources name brittleness, composition shift and loss of strain as the main ways a Ni-Mn-Ga part stops working.
      level: 2
      verdict: Brittleness and composition
      points:
        - label: Brittleness
          line: The 2000 MRS-J paper names inherent brittleness as one of the problems to overcome before practical use.
        - label: Composition drift
          line: The martensitic transition temperature rises from 201 K at x = 0 to 342 K at x = 0.19, and the Curie temperature falls toward it.
    - title: Handling and storage
      points:
        - label: Melting
          line: Ingots are arc melted under argon, homogenized at 1073 K for 48 to 72 hours, and quenched.
        - label: Sample position
          line: A crystal cut from the middle of the boule gave no magnetically induced strain in the review, so cut position matters.
  why: Ni-Mn-Ga is a ferromagnetic shape-memory alloy. Its martensite can be reoriented by a magnetic field, so it can change shape fast without a heating cycle. Single crystals show 5.1 to 7.3 % magnetically induced strain in one review table, and the Curie temperature of stoichiometric Ni2MnGa is about 370 K.
  uses:
    - where: Magnetic actuators
      line: The 2000 MRS-J paper calls Ni-Mn-Ga a good candidate for magnetic actuator materials, and the 2003 review notes that actuators and sensors based on this class of alloy need more durability first.
    - where: Magnetocaloric cooling
      line: A 2005 conference paper reports 9 J/kgK at 338 K and 11 J/kgK at 344 K in a 26 kOe field.
  can_do:
    - label: Change shape by field
      line: Single crystals of Ni48 Mn31 Ga21, Ni49.8 Mn28.5 Ga21.7 and Ni48.2 Mn30.8 Ga21 gave 5.1, 6.0 and 7.3 % magnetically induced strain.
      value: 5.1 to 7.3 %
    - label: Work near room temperature
      line: The Curie temperature of stoichiometric Ni2MnGa is about 370 K, and the transition temperature Tm of the series runs from 201 K to 342 K.
      value: 201 to 342 K
    - label: Cool by magnetic entropy change
      line: A magnetic entropy change of 9 J/kgK at 338 K was measured in a 26 kOe field, and 11 J/kgK at 344 K when the field was removed.
      value: 9 and 11 J/kgK
  compare: Among the Ni2+xMn1-xGa series, the martensitic transition temperature rises with nickel content, from 201 K at x = 0 to 342 K at x = 0.19, while the Curie temperature falls toward it. Strain values come from single crystals in one review table and from a nonmodulated single crystal in a 2009 paper, so they are not directly comparable with the table values.
  compare_rows:
    - label: Curie temperature
      benchmark: curie_temperature
    - label: Martensitic transition temperature
      benchmark: martensitic_transition_temperature
    - label: Magnetic field induced strain
      benchmark: magnetic_field_induced_strain
  handling:
    - Homogenize the ingot at 1073 K for 48 to 72 hours under argon, then quench.
    - Check the composition by EDX, since Tm moves with composition.
    - Treat gallium as corrosive to metals (H290) and follow the supplier SDS.
  good_for:
    - Single-crystal magnetic actuators where stroke is set by a field, with 5.1 to 7.3 % strain in one review table.
    - Magnetocaloric refrigerant studies near room temperature, with 9 and 11 J/kgK entropy changes in a 26 kOe field.
  watch_out:
    - 'Brittleness: the 2000 MRS-J paper names it as a main obstacle to practical use.'
    - 'Composition: Tm moves from 201 K to 342 K across the series.'
    - 'Cut position: a crystal cut from the middle of the boule gave no strain in the review.'
    - 'Hazards: the SDS codes used here come from a nickel alloy and gallium, not a Ni-Mn-Ga SDS.'
  verdict: Ni-Mn-Ga is a magnetically driven shape-memory Heusler alloy. Its strain is set by a magnetic field, not by heat, and its single crystals gave 5.1 to 7.3 % strain in one review table. The record still lacks density, elastic modulus, corrosion data, a Ni-Mn-Ga SDS, designations and any space-environment data, so it is a draft.
  recipe:
    line: Ni-Mn-Ga is made by argon arc melting of the three metals, followed by homogenization at 1073 K for 48 to 72 hours in argon and quenching into room-temperature water (Tsuchiya 2000). Composition is set by the Ni, Mn and Ga ratio, with stoichiometric Ni2MnGa as the reference.
    parts:
      - name: Nickel
        symbol: Ni
        role: Sets the transition temperature and Curie temperature; excess nickel raises Tm and lowers TC
        share_note: 2 of 4 formula positions in stoichiometric Ni2MnGa (x = 0), then Ni2+xMn1-xGa to x = 0.19
        source: khovailo2004
        where: Formula Ni2+xMn1-xGa, Introduction
      - name: Manganese
        symbol: Mn
        role: Carries the magnetic moment of the Heusler lattice and sets the Mn-rich compositions with the largest strain
        share_note: 1 of 4 formula positions in stoichiometric Ni2MnGa (x = 0); lower in the Ni-rich series
        source: khovailo2004
        where: Formula Ni2+xMn1-xGa, Introduction
      - name: Gallium
        symbol: Ga
        role: Heusler third element; its content is fixed by the Mn-Ni balance in the studied series
        share_note: 1 of 4 formula positions in stoichiometric Ni2MnGa (x = 0)
        source: khovailo2004
        where: Formula Ni2MnGa, Introduction
supply:
  - subject: Nickel, world mine production 2025e (3,900,000 t; Indonesia 2,600,000 t, Philippines 270,000 t, Russia 200,000 t, New Caledonia 140,000 t); shares calculated by Space Mushroom from the printed tonnages
    abundance: World nickel reserves above 140,000,000 t (USGS 2026, reserves table)
    producers:
      - country: Indonesia
        share_percent: 66.7
        year: 2025
      - country: Philippines
        share_percent: 6.9
        year: 2025
      - country: Russia
        share_percent: 5.1
        year: 2025
    critical_lists: []
    recycling: 'USGS 2026: most secondary nickel was in the form of nickel content of stainless-steel scrap, and most recycled nickel was used to produce new alloys.'
    substitutes: []
    source: usgs-ni
    where: World Mine Production and Reserves table, 2024 and 2025e columns
  - subject: Manganese, world mine production 2025e (20,000 thousand t, manganese content; South Africa 7,600, Gabon 5,000, Ghana 2,000); shares calculated by Space Mushroom from the printed tonnages
    abundance: Land-based manganese resources are large but irregularly distributed; world reserves 1,800,000 thousand t (USGS 2026)
    producers:
      - country: South Africa
        share_percent: 38
        year: 2025
      - country: Gabon
        share_percent: 25
        year: 2025
      - country: Ghana
        share_percent: 10
        year: 2025
    critical_lists: []
    recycling: 'USGS 2026: manganese was recycled incidentally as a constituent of ferrous and nonferrous scrap.'
    substitutes: []
    source: usgs-mn
    where: World Mine Production (manganese content) and Reserves table, 2025e column
  - subject: Gallium, world primary low-purity production 2024 (848,000 kg; China 839,000 kg, Japan 3,000 kg, Russia 6,000 kg); shares calculated by Space Mushroom from the printed kilograms
    abundance: Gallium is produced mainly as a byproduct of bauxite processing; bauxite contains about 50 parts per million gallium (USGS 2026)
    producers:
      - country: China
        share_percent: 98.9
        year: 2024
      - country: Russia
        share_percent: 0.7
        year: 2024
      - country: Japan
        share_percent: 0.4
        year: 2024
    critical_lists: []
    recycling: 'USGS 2026: old scrap, none; substantial new scrap from GaAs device manufacture was reprocessed at one New York facility.'
    substitutes: []
    source: usgs-ga
    where: World Low-Purity Production table, 2024 column; World Resources paragraph
documents:
  - title: Shape memory ferromagnets (Vasil'ev et al., arXiv cond-mat/0311433, 2003)
    type: paper
    url: https://arxiv.org/pdf/cond-mat/0311433
    year: 2003
  - title: Magnetic properties and magnetostructural phase transitions in Ni2+xMn1-xGa shape memory alloys (Khovailo et al., arXiv cond-mat/0405134, 2004)
    type: paper
    url: https://arxiv.org/pdf/cond-mat/0405134
    year: 2004
  - title: Large Magnetic-Field-Induced Strains in Ni-Mn-Ga Nonmodulated Martensite (Chernenko et al., Applied Physics Letters 2009)
    type: paper
    url: https://scholarworks.boisestate.edu/mse_facpubs/40
    year: 2009
  - title: Magnetocaloric effect in Ni-Mn-Ga Heusler alloys (Aliev et al., 2005)
    type: paper
    url: https://iifiir.org/en/fridoc/magnetocaloric-effect-in-ni-mn-ga-heusler-alloys-22416
    year: 2005
  - title: Effect of Fourth Elements on Phase Transformations in Ni-Mn-Ga Heusler Alloys (Tsuchiya et al., Trans. MRS-J 25, 2000)
    type: paper
    url: https://www.mrs-j.org/pub/tmrsj/vol25_no2/vol25_no2_517.pdf
    year: 2000
  - title: Structural, Thermal and Magnetic Characterization of Polycrystalline Ni-Mn-Ga Ferromagnetic Shape Memory Alloys (Materials Research, 2023)
    type: paper
    url: https://www.scielo.br/j/mr/a/kgNcGQ55wgqyJngcwjVm8Qk/?lang=en
    year: 2023
  - title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Manganese'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-manganese.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Gallium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-gallium.pdf
    year: 2026
  - title: Gallium safety data sheet (Angstrom Sciences, CAS 7440-55-3)
    type: sds
    url: https://angstromsciences.com/wp-content/uploads/files/SDS/Gallium.pdf
  - title: Nickel Based Metal Alloys safety data sheet (Greenville Metals, PCC Forged Products)
    type: sds
    url: https://www.pccforgedproducts.com/documents/greenville/sds/nickel-based-metal-alloys-sds.pdf
gaps:
  - No density or elastic modulus for Ni-Mn-Ga was read in a source in this run. The Ni2MnGa searches returned no density, and the Vasil'ev and Khovailo papers give none.
  - No corrosion, oxidation or ageing data for Ni-Mn-Ga was found, so the corrosion list is empty.
  - No UNS, EN, JIS, AISI, ASTM or other designation for Ni-Mn-Ga was printed in a source read in this run, so designations is empty.
  - No safety data sheet for the Ni-Mn-Ga alloy itself was read. The nickel-based alloy SDS (Greenville Metals) is a related product, not the same grade, and the Mn SDS was not read.
  - The Wikipedia Ni-Mn-Ga page was not used for values. The Heusler and magnetic shape-memory Wikipedia pages are secondary and were read only for composition and history.
  - The Springer review (s40830-024-00510-z) redirected to a sign-in page, and the PubChem gallium page returned a verification page, so no PubChem GHS entry was read.
  - The Dubenko et al. 2012 abstract gives magnetic entropy change values for Ni-Mn-based Heusler alloys with In, Sn and Sb, not Ni-Mn-Ga, so none of its numbers were used.
  - The full table of Materials Research 2023 (Batista et al.) was not read; only its abstract was, which gives compositions and phases but no property values.
  - The Ni-Mn-Ga temperature range, fatigue life, output stress and cycling figures in the Wikipedia magnetic shape-memory page are secondary, and were not entered as values.
  - No space-environment data (outgassing, atomic oxygen, radiation, thermal cycling in orbit) for Ni-Mn-Ga was found in a source read in this run.
  - 'Critical-mineral list status for nickel, manganese and gallium was not confirmed: the USGS texts give no list, and the gallium text does not name one.'
  - 'Custom property names used because no canonical name exists: martensitic_transition_temperature, latent_heat_martensitic_transition, magnetic_field_induced_strain, magnetocrystalline_anisotropy_constant and magnetic_entropy_change.'
  - Table I values in the Vasil'ev review are from a 2003 review table and are cited to the original reference numbers, not re-measured here. The supply shares are calculated by Space Mushroom from printed tonnages.
sources:
  khovailo2004:
    title: Magnetic properties and magnetostructural phase transitions in Ni2+xMn1-xGa shape memory alloys (Khovailo et al., Phys. Rev. B 70, 174413, 2004)
    url: https://arxiv.org/pdf/cond-mat/0405134
    year: 2004
    kind: paper
    license: arXiv preprint (cited, not reproduced)
  vasil2003:
    title: Shape memory ferromagnets (Vasil'ev et al., arXiv cond-mat/0311433, 2003)
    url: https://arxiv.org/pdf/cond-mat/0311433
    year: 2003
    kind: paper
    license: arXiv preprint (cited, not reproduced)
  chernenko2009:
    title: Large Magnetic-Field-Induced Strains in Ni-Mn-Ga Nonmodulated Martensite (Chernenko, Chmielus, Mullner, Applied Physics Letters 95, 104103, 2009)
    url: https://scholarworks.boisestate.edu/mse_facpubs/40
    year: 2009
    kind: paper
    license: author repository (cited, not reproduced)
  aliev2005:
    title: Magnetocaloric effect in Ni-Mn-Ga Heusler alloys (Aliev et al., 1st International Conference on Magnetic Refrigeration at Room Temperature, 2005)
    url: https://iifiir.org/en/fridoc/magnetocaloric-effect-in-ni-mn-ga-heusler-alloys-22416
    year: 2005
    kind: paper
    license: IIR document (cited, not reproduced)
  tsuchiya2000:
    title: Effect of Fourth Elements on Phase Transformations in Ni-Mn-Ga Heusler Alloys (Tsuchiya et al., Trans. Mater. Res. Soc. Jpn. 25, 2000)
    url: https://www.mrs-j.org/pub/tmrsj/vol25_no2/vol25_no2_517.pdf
    year: 2000
    kind: paper
    license: open access (cited, not reproduced)
  batista2023:
    title: Structural, Thermal and Magnetic Characterization of Polycrystalline Ni-Mn-Ga Ferromagnetic Shape Memory Alloys (Batista et al., Materials Research 26, 2023)
    url: https://www.scielo.br/j/mr/a/kgNcGQ55wgqyJngcwjVm8Qk/?lang=en
    year: 2023
    kind: paper
    license: open access (cited, not reproduced)
  wiki-msma:
    title: Magnetic shape-memory alloy, Wikipedia (composition and history only)
    url: https://en.wikipedia.org/wiki/Magnetic_shape-memory_alloy
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  usgs-ni:
    title: Mineral Commodity Summaries 2026, Nickel (USGS, February 2026)
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mn:
    title: Mineral Commodity Summaries 2026, Manganese (USGS, February 2026)
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-manganese.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-ga:
    title: Mineral Commodity Summaries 2026, Gallium (USGS, February 2026)
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-gallium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  sds-ga:
    title: Gallium safety data sheet (Angstrom Sciences, CAS 7440-55-3)
    url: https://angstromsciences.com/wp-content/uploads/files/SDS/Gallium.pdf
    kind: datasheet
    license: manufacturer safety data sheet (cited, not reproduced)
  sds-ni-alloy:
    title: Nickel Based Metal Alloys safety data sheet (Greenville Metals, PCC Forged Products)
    url: https://www.pccforgedproducts.com/documents/greenville/sds/nickel-based-metal-alloys-sds.pdf
    kind: datasheet
    license: manufacturer safety data sheet (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 19
  unreachable: 3
  caveats: 5
  note: 'Values were read by an AI assistant on 2026-10-26 from the papers, reports and safety data sheets named in each entry. Unreachable: the Springer review (sign-in redirect), the PubChem gallium page (verification page), and the Sigma-Aldrich SDS (timeout). Caveats: the hazard codes come from a nickel-based alloy SDS, not a Ni-Mn-Ga SDS; the Table I values are from a 2003 review and cite original references; the magnetocaloric numbers come from a conference summary with no composition; the strain values are for single crystals and a nonmodulated crystal, not comparable; the supply shares are calculated.'