{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.magnetite-nanoparticle","code":"thing-q3870166","url":"https://ver.cy/models/thing/q3870166/","name":"magnetite nanoparticle","alternateNames":["magnetic nanobead"],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.OBJ"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A magnetite nanoparticle is a nanoscale particle composed principally of the mixed-valence iron oxide Fe₃O₄, whose inverse-spinel crystal structure supports ferrimagnetic ordering and whose size can permit superparamagnetic behavior.","purpose":"Enable an agent to identify a magnetite nanoparticle, assess its phase, dimensions, surface and magnetic state, and select evidence-supported handling or use.","scope":{"in":["Magnetite phase identification, iron valence and partial oxidation","Primary-particle dimensions, morphology and internal crystallite structure","Surface chemistry, attached coatings and core-shell boundaries","Magnetic response under specified temperature, field and measurement timescale","Aggregation, dispersion behavior and changes during storage or use","Sample provenance and evidence supporting application-specific suitability"],"out":["Bulk magnetite mineralogy, ore deposits and mining operations","Maghemite, hematite and other iron oxide nanoparticles as independent material kinds","Complete ferrofluid formulations and their bulk engineering properties","Synthesis reactors and manufacturing processes as operational systems","MRI scanners, magnetic separators and hyperthermia equipment","Clinical treatment protocols, patient outcomes and finished-product authorization"],"boundaries":[]},"distinguishingFeatures":["Require phase and iron-valence evidence consistent with magnetite, nominally Fe3O4; a magnetic response alone cannot distinguish it from neighboring magnetic iron oxides. [Primary characterization study](https://www.nature.com/articles/srep30969)","Measure primary-particle dimensions directly and state the nanoscale convention used; crystallite size and hydrodynamic diameter answer different identification questions.","Resolve whether the specimen is one particle, a multicrystallite particle or a cluster of particles before assigning its size and internal structure.","Check oxidation state independently of external size or shape: oxidation can occur without an observable change in those dimensions. [Oxidation study](https://www.nature.com/articles/s41467-021-26566-4)","Establish superparamagnetic or blocked behavior under recorded measurement conditions; do not use the label 'superparamagnetic iron oxide' as proof of magnetite composition."],"structure":{"bundles":[{"id":"magnetite-identity","name":"Magnetite identity","description":"Establish the chemical and crystalline identity of the nanoscale iron oxide.","layers":[{"id":"phase-and-valence","name":"Phase and valence","description":"Connect structural measurements with iron oxidation-state evidence.","findings":[{"id":"magnetite-assignment","name":"Magnetite assignment","description":"Record the proposed phase assignment, supporting observations and unresolved alternatives.","questions":[{"text":"Which structural and valence-sensitive measurements support magnetite rather than maghemite or a mixed iron oxide?","id":"magnetite-assignment-q01","kind":"definition"},{"text":"What Fe(II)/total Fe fraction was measured, with what uncertainty and sensitivity to surface versus interior?","id":"magnetite-assignment-q02","kind":"measurement"}]}]},{"id":"oxidation-and-phase-boundary","name":"Oxidation and phase boundary","description":"Represent nonstoichiometry, oxidation gradients and secondary phases.","findings":[{"id":"retained-magnetite","name":"Retained magnetite","description":"Make explicit how much of the identified particle remains attributable to magnetite.","questions":[{"text":"Does the evidence resolve homogeneous partial oxidation, a magnetite core with an oxidized shell, or separate phases?","id":"retained-magnetite-q01","kind":"boundary"},{"text":"What evidence would require reassignment to a mixed-phase particle or another iron oxide entry?","id":"retained-magnetite-q02","kind":"boundary"}]}]}]},{"id":"particle-geometry","name":"Particle geometry","description":"Separate primary-particle dimensions, crystalline domains and associated particles.","layers":[{"id":"primary-particle-dimensions","name":"Primary-particle dimensions","description":"Describe the material boundary and geometry of individual particles.","findings":[{"id":"nanoscale-membership","name":"Nanoscale membership","description":"Document the size convention and observations supporting classification as a nanoparticle.","questions":[{"text":"What are the primary-particle dimensions and shape distribution, and does the measured boundary include the coating?","id":"nanoscale-membership-q01","kind":"measurement"},{"text":"Which nanoscale definition is being applied, particularly for elongated particles or broad size distributions?","id":"nanoscale-membership-q02","kind":"definition"}]}]},{"id":"internal-and-associated-structure","name":"Internal and associated structure","description":"Distinguish coherent crystal domains from physical particles and clusters.","findings":[{"id":"particle-domain-correspondence","name":"Particle-domain correspondence","description":"Relate microscopy, diffraction and dispersion measurements to the entities each measures.","questions":[{"text":"Does a microscopy-resolved particle contain one crystalline domain or several, and how does that compare with diffraction-derived crystallite size?","id":"particle-domain-correspondence-q01","kind":"measurement"},{"text":"Does a larger observed entity represent fused material, an aggregate or a reversible association of separate nanoparticles?","id":"particle-domain-correspondence-q02","kind":"boundary"}]}]}]},{"id":"surface-and-dispersion","name":"Surface and dispersion","description":"Represent the exposed or coated magnetite interface in a specified surrounding medium.","layers":[{"id":"coating-and-accessibility","name":"Coating and accessibility","description":"Identify surface-bound material and distinguish it from unbound formulation components.","findings":[{"id":"surface-attachment","name":"Surface attachment","description":"Record coating identity, attachment evidence and accessible surface functionality.","questions":[{"text":"Which ligands or shells are attached, and what evidence distinguishes attached material from residual free molecules?","id":"surface-attachment-q01","kind":"measurement"},{"text":"Which surface groups or magnetite sites remain accessible for the proposed conjugation or adsorption step?","id":"surface-attachment-q02","kind":"action"}]}]},{"id":"medium-dependent-association","name":"Medium-dependent association","description":"Track dispersed size and association as functions of preparation and medium.","findings":[{"id":"dispersion-state","name":"Dispersion state","description":"Describe the measured dispersed population without equating hydrodynamic size with core size.","questions":[{"text":"What hydrodynamic size distribution and zeta potential were measured at the stated pH, ionic strength, concentration and temperature?","id":"dispersion-state-q01","kind":"measurement"},{"text":"After medium exchange, storage or magnetic collection, can the original dispersion state be restored by a documented procedure?","id":"dispersion-state-q02","kind":"action"}]}]}]},{"id":"magnetic-behavior","name":"Magnetic behavior","description":"Capture field response, relaxation and the evidence required for magnetic manipulation.","layers":[{"id":"field-response-and-relaxation","name":"Field response and relaxation","description":"Qualify magnetic observations by conditions, timescale and normalization.","findings":[{"id":"conditional-magnetic-state","name":"Conditional magnetic state","description":"Record magnetization and magnetic-state evidence without assuming universal superparamagnetism.","questions":[{"text":"What magnetization curve, coercivity and remanence were measured, at which temperature and with which mass normalization?","id":"conditional-magnetic-state-q01","kind":"measurement"},{"text":"What temperature-dependent or frequency-dependent evidence supports the assigned relaxation state on the relevant observation timescale?","id":"conditional-magnetic-state-q02","kind":"measurement"}]}]},{"id":"magnetic-operation","name":"Magnetic operation","description":"Connect proposed field-driven actions to measurements on the relevant sample.","findings":[{"id":"field-driven-performance","name":"Field-driven performance","description":"Keep magnetic collection and alternating-field heating as separately demonstrated capabilities.","questions":[{"text":"What collection fraction and collection time were demonstrated for the stated field gradient, geometry, medium and concentration?","id":"field-driven-performance-q01","kind":"measurement"},{"text":"If heating is proposed, what loss power was measured at the stated field amplitude and frequency, with what mass basis and thermal correction?","id":"field-driven-performance-q02","kind":"action"}]}]}]},{"id":"history-and-use-readiness","name":"History and use readiness","description":"Connect preparation, aging and sample-specific evidence to a proposed use.","layers":[{"id":"preparation-and-aging","name":"Preparation and aging","description":"Track conditions that may change phase, coating or association state.","findings":[{"id":"characterized-material-history","name":"Characterized material history","description":"Tie each measurement to an identifiable batch and its treatment history.","questions":[{"text":"Which synthesis, purification and coating records identify this batch, including residual precursors or processing agents?","id":"characterized-material-history-q01","kind":"provenance"},{"text":"What before-and-after evidence shows whether oxygen exposure, heating, drying or storage changed phase, coating integrity or aggregation?","id":"characterized-material-history-q02","kind":"measurement"}]}]},{"id":"application-evidence","name":"Application evidence","description":"Identify the measurements and unresolved conditions relevant to a specific proposed operation.","findings":[{"id":"sample-specific-suitability","name":"Sample-specific suitability","description":"Separate demonstrated material capabilities from intended applications and formulation-level claims.","questions":[{"text":"Which proposed use has supporting measurements on this batch or an explicitly justified equivalent formulation?","id":"sample-specific-suitability-q01","kind":"provenance"},{"text":"Before that use, which unresolved checks concerning iron release, residual reagents, exposure, coating stability or performance require resolution?","id":"sample-specific-suitability-q02","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of magnetite nanoparticle this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of magnetite nanoparticle this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of magnetite nanoparticle this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of magnetite nanoparticle this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of magnetite nanoparticle this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of magnetite nanoparticle this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of magnetite nanoparticle this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Describe magnetite nanoparticles and their uses in research, imaging and water treatment from reliable sources.","Record samples, coatings and storage in a laboratory the agent is authorized to manage."],"mustNot":["Present research products as approved medical treatments.","Release nanoparticles into drains or the environment.","Handle dry nanopowders without the site's controls for inhalation.","Overstate early research in a way that misleads patients or investors."],"requiresHuman":["Use of nanoparticles in animals or people."]},"ethics":{"considerations":["The long-term health effects of inhaled nanoparticles are not fully known.","Medical hype can mislead patients."],"affectedParties":["Laboratory workers","Patients in trials","Ecosystems"]},"owners":{"steward":"The laboratory or producer that holds the material.","roles":[],"masterSystems":["Chemical inventories and safety data sheet systems"]},"relations":[{"target":"Q111384401","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.magnetite-nanoparticle","Wikidata: Q3870166 (https://www.wikidata.org/wiki/Q3870166)"]},"properties":{"applicability":"required","items":["Phase assignment: magnetite; partially oxidized magnetite; mixed phase; unresolved, with methods and confidence","Iron valence balance: Fe(II)/total Fe molar fraction, with uncertainty and sampling depth","Primary-particle dimensions: nm along relevant axes; distribution and number of particles measured","Crystallite structure: single crystalline; multicrystalline; defective; unresolved, with characterization method","Surface coating: linked coating or ligand identity, attachment evidence, coverage and thickness where measured","Hydrodynamic size: nm, with distribution weighting, medium, temperature, concentration and method","Electrokinetic potential: zeta potential in mV, with pH, electrolyte composition and measurement model","Magnetization response: A·m²/kg with explicit mass basis, applied field, temperature and saturation criterion","Magnetic relaxation state: superparamagnetic; blocked; mixed population; unresolved, at stated temperature and observation timescale","Particle association state: dispersed; reversibly associated; persistently aggregated; sedimented; unresolved","Transformation history: dated links to oxygen exposure, heating, medium changes and before/after characterization","Material concentration: mg Fe/mL or mg iron oxide/mL, with explicit basis and assay"]},"recognition":{"applicability":"required","items":["A black powder or dark brown liquid suspension that is drawn towards a magnet."]},"capabilities":{"applicability":"required","items":["Request complementary phase and valence measurements when the magnetite assignment is uncertain.","Compare samples using matched size definitions, magnetic conditions and mass normalization.","Select and verify coating or ligand modification for a specified medium.","Evaluate magnetic collection and redispersion under a documented field gradient.","Detect aging or oxidation and trigger recharacterization before reuse.","Assess a proposed imaging, heating, adsorption or separation use against measurements from the relevant formulation."]},"hazards":{"applicability":"required","items":["Fine powders can be inhaled.","Particles can clump and lose their useful properties."]},"interfaces":{"applicability":"required","items":["ISO 14971, issued by the International Organization for Standardization, applies to risk management when these particles form part of a medical device.","ISO 10993-1, issued by the International Organization for Standardization, provides the framework for biological evaluation when these particles form part of a body-contacting medical device."]},"context":{"applicability":"required","items":["These particles are studied and used in magnetic separation, surface-functionalized assays and materials research.","Biomedical research investigates suitable formulations for imaging contrast, targeted delivery and magnetic heating.","Their suitability depends on particle dimensions, aggregation, surface chemistry and the surrounding medium."]}},"sources":[{"title":"Wikidata item Q3870166: magnetite nanoparticle","url":"https://www.wikidata.org/wiki/Q3870166","note":"identity and sense of the item"},{"title":"Wikipedia: Magnetic nanoparticles","url":"https://en.wikipedia.org/wiki/Magnetic_nanoparticles","note":"general description of the item"}],"openQuestions":["Which existing Vercy models already own magnetite, iron oxide nanoparticles and coated composite particles, and what should this entry inherit from them?","Which nanoscale convention should govern this registry entry, including elongated particles, multicore structures and distributions extending beyond its limits?","What minimum complementary measurements and uncertainty criteria are sufficient to distinguish magnetite from maghemite in small, coated or partially oxidized samples?","At what measured degree or spatial pattern of oxidation should the particle be classified as mixed phase or linked to another material entry?","Which intended applications need dedicated extensions for performance, exposure and acceptance criteria beyond this material model?"],"resources":{"spec":"/models/things/publications/thing-q3870166/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q3870166/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T11:07:43Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:30+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}