1. The short version

• The starting point is an experiment on an equimolar mixture of the five oxides MgO, CoO, NiO, CuO and ZnO, which changed from a multiphase state to a single-phase rocksalt structure, absorbing heat (an endotherm), in the window of 825–875 °C. It was single-phase at 1,000 °C, returned to multiphase at 750 °C and became single-phase again at 1,000 °C; no set of four components made by removing one of the five became single-phase; and the local structure was randomSourced [Source 1]
• Whether something may be called “entropy-stabilised” depends on the kind of evidence. There are four: reversibility, endotherm, control by changing components, and local structure. For a spinel-type high-entropy oxide there is a report that cations enter their sites in a way that differs from perfect randomness [Source 3], and the questions about entropy’s role remain open [Source 2]. Among carbides, of the twelve candidate compositions nine became single-phase rocksalt [Source 6]
• Figures for hardness, resistance to heat flow and lithium-ion mobility are results for that material under those conditions. For example, the hardness of (Hf-Ta-Zr-Nb)C, 36.1 ± 1.6 GPa, is reported to be higher than 32.9 ± 1.8 GPa for binary (Hf-Ta)C and 31.5 ± 1.3 GPa for HfC [Source 5]. Whether this is “because of entropy” has to be shown by separate evidence

2. The starting point — (Mg,Co,Ni,Cu,Zn)O of Rost et al.

The paper by Rost et al. (Nature Communications, 2015) showed by experiment the idea that, by filling one sublattice (for an oxide, the cation sites) with many different cations, configurational disorder can be designed into a composition and new phases can be found. Using a five-component oxide, the paper states that it demonstrated that entropy dominates the thermodynamic landscape and drives a reversible solid-state transformation between a multiphase and a single-phase state, and that in the single-phase state the cation distribution is random and homogeneousSourced [Source 1].

The specimen “E1” is an equimolar mixture of MgO, CoO, NiO, CuO and ZnO. The paper gives its reasons for the choice as including that the crystal structures, electronegativities and cation coordinations are not uniform and that some pairs, such as MgO-ZnO and CuO-NiO, do not dissolve extensively in each other [Source 1]. The specimens were made by mixing the powders (a shaker mill with yttria-stabilised zirconia media, at least 2 hours), pressing them into 1.27 cm pellets and heat-treating them in air [Source 1].

• Phases by temperature: pellets equilibrated at 700–1,100 °C (50 °C steps) and quenched showed two phases, rocksalt and tenorite (the CuO structure), at 700 °C, with the tenorite fraction falling as temperature rose, and converted completely to single-phase rocksalt between 850 and 900 °C [Source 1]
• Reversibility: a single-phase specimen equilibrated at 1,000 °C went back to multiphase when re-annealed at 750 °C and became single-phase again on returning to 1,000 °C. The paper says reversibility is a requirement of entropy-driven transitions [Source 1]
• Endotherm: when in situ X-ray diffraction and differential scanning calorimetry (DSC) were run at the same heating rate, the diffraction collapsed to single-phase rocksalt at 825–875 °C and a pronounced endotherm appeared in the same window. Mass fell by about 1.5%, which the paper explains by some spinel becoming rocksalt, with trivalent cations reduced to divalent and oxygen released [Source 1]
• Control by changing components: at 875 °C (the threshold temperature for complete solubility) for 12 hours, the sets of four components made by removing one from the five never became single-phase. The paper also tests the prediction that moving one component’s ratio away from equimolar reduces the number of configurations and raises the transition temperature, with experiments that change the ratios [Source 1]
• Local structure: by EXAFS (extended X-ray absorption fine structure), the nearest cation–oxygen distances were identical (within ±0.01 Å) and the local structures to about the seventh neighbour were similar, from which the paper concludes that the cation distribution is random [Source 1]

3. The evidence needed to call it “entropy-stabilised”

To claim “stabilised by entropy”, the experiment of Rost et al. (Section 2) put together, for one material, four checks: reversibility, endotherm, control by changing components, and local structure [Source 1]. Using these as a yardstick lets us compare how far other reports have confirmed the same things.

• Spinel type: Sarkar et al. studied how cations enter their sites in the spinel-type high-entropy oxide (Co_0.2Cr_0.2Fe_0.2Mn_0.2Ni_0.2)₃O₄ by soft X-ray magnetic circular dichroism, hard X-ray absorption, Mössbauer spectroscopy, neutron powder diffraction and SQUID magnetometry. The model derived, (Co_0.6Fe_0.4)(Cr_0.3Fe_0.1Mn_0.3Ni_0.3)₂O₄, deviates significantly from the long-assumed “entropy-driven distribution of cations without preference”, they report, and they argue that a competition between crystal-field stabilisation energy and configurational entropy decides site occupationSourced [Source 3]
• Open questions: the viewpoint article by Sarkar et al. (Scripta Materialia, 2020) discusses the open queries about the roles of entropy, enthalpy, individual elements and the synergy of several elements in high-entropy oxides, and what distinguishes them from conventional oxides [Source 2]
• Carbides: Sarker et al. proposed a descriptor, the entropy forming ability, based on first-principles calculation, and report that it correctly predicted by experiment how easily five-metal carbides can be synthesised as rocksalt, high-entropy homogeneous phases [Source 4]. Harrington et al. made twelve equiatomic five-metal carbides by high-energy ball milling and spark plasma sintering and report that when sintered at 2,473 K, nine of the twelve became truly single-phase rocksalt (B1), and that (V_0.2Nb_0.2Ta_0.2Mo_0.2W_0.2)C is a “likely candidate” for an entropy-stabilised carbide [Source 6]
• Single-phase at high temperature does not mean stable at room temperature: Castle et al. made (Hf-Ta-Zr-Ti)C and (Hf-Ta-Zr-Nb)C, say that the mismatch in lattice parameter of the component monocarbides is a key to predicting whether a single-phase solid solution forms, and, from one sample that decomposed chemically, suggest a miscibility gap and that the system is not thermodynamically stable to room temperature [Source 5]

4. Carbides and borides — ultra-high-temperature ceramics and hardness

Borides: Gild et al. made seven equimolar five-component metal diborides by high-energy ball milling and spark plasma sintering, and report that six of them (for example (Hf_0.2Zr_0.2Ta_0.2Nb_0.2Ti_0.2)B₂) became virtually one solid-solution phase of the hexagonal AlB₂ structure. They obtained more than 92% of theoretical density, confirmed by aberration-corrected scanning transmission electron microscopy a two-dimensional layered structure in which high-entropy metal layers are separated by rigid boron nets, and say that in initial assessments both the hardness and the oxidation resistance are generally higher/better than the average of five individual diboridesSourced [Source 7].

Carbides: Sarker et al. report that some five-metal carbides have hardness up to 50% higher than rule-of-mixtures estimates [Source 4]. Harrington et al. examined seven carbides by nanoindentation and state that the hardness of the high-entropy carbides is significantly higher than the rule-of-mixtures average of the constituent binary carbides and than the highest value among them, with a correlation to the electronic structure [Source 6]. Castle et al. obtained (Hf-Ta-Zr-Nb)C as a single phase at 99% density (after optimisation) by ball milling and spark plasma sintering, and by nanoindentation found 36.1 ± 1.6 GPa. HfC, the hardest monocarbide, is 31.5 ± 1.3 GPa and binary (Hf-Ta)C is 32.9 ± 1.8 GPa [Source 5].

5. Resistance to heat flow and ion conduction — fluorite-type, pyrochlore-type, perovskite-type, lithium conduction

Fluorite-type oxides: Gild et al. made eleven fluorite-type oxides with five principal cations (adding, as a starting baseline, the four-principal-cation (Hf_0.25Zr_0.25Ce_0.25Y_0.25)O_2-δ) by high-energy ball milling, spark plasma sintering and annealing in air, and report that eight compositions became single-phase fluorite solid solutions. Most could be sintered to high relative density. Compared with 8 mol% Y₂O₃-stabilised zirconia (8YSZ), they had lower electrical conductivity, comparable hardness and lower thermal conductivity, and the authors ascribe the low thermal conductivity to strong phonon scattering by multiple cations and strained lattices (“presumably”, that is, an inference)Sourced [Source 8].

Pyrochlore-type oxides: Wright et al. made 18 medium- and high-entropy pyrochlores and measured thermal conductivity and Young’s modulus. They report reductions in thermal conductivity of up to 35% with the modulus retained. The thermal conductivity correlated well with a modified size-disorder parameter, which they propose as a useful descriptor for designing thermally insulating medium- and high-entropy ceramics. They mention potential use in thermal barrier coatingsSourced [Source 9].

Perovskite-type oxides: Jiang et al. published a paper on “a new class of high-entropy perovskite oxides” (only the title was checked here, not the content) [Source 10].

Lithium and sodium conduction: Bérardan et al. report that in high-entropy oxides of the formula (MgCoNiCuZn)_1−x−yGa_yA_xO (A = Li, Na, K), impedance spectroscopy showed “superionic” Li⁺ mobility (above 10⁻³ S/cm) at room temperature and fast Na⁺ mobility (5×10⁻⁶ S/cm)Sourced [Source 11]. These are impedance-spectroscopy values, not performance in a battery.

The overview by Toher et al. (MRS Bulletin, 2022) gives, as examples where disorder enhances properties, higher hardness and yield stress by solid-solution strengthening, higher thermochemical stability from chemically disordered mixtures’ preference for high-symmetry superlattices, and lower lattice thermal conductivity from force-constant disorder without loss of strength and stiffness, and extends the range of applications from wear-resistant coatings, thermal and environmental barriers, catalysts and batteries to thermoelectrics and nuclear energy management [Source 13].

6. Battery electrodes — conversion-type oxides

The paper by Sarkar et al. (Nature Communications, 2018) tested (Co_0.2Cu_0.2Mg_0.2Ni_0.2Zn_0.2)O (rocksalt, phase purity checked by X-ray diffraction with Rietveld refinement) as the active material of a lithium-cell electrode (63 wt% of the electrode) over a voltage range of 0.01–3 V against Li⁺/LiSourced [Source 12].

• How the reaction is thought to work: either insertion of Li into the rocksalt structure or a conversion reaction forming metal and Li₂O is possible, and since transition-metal oxides are prone to the latter, the authors judge reversible conversion to be reasonable. They believe the capacity lies in the range of divalent-oxide conversion materials (700–1,000 mAh/g), but because the reactions are not known they also say the theoretical capacity cannot be predicted with high accuracy [Source 12]
• Capacity: after stepping the current up to 3 A/g and back to 0.1 A/g, the capacity recovered and even grew, reaching 770 mAh/g after 100 cycles. The paper explains the rise with cycling by the “activation” typical of conversion-type materials with large particles [Source 12]
• Coulombic efficiency: 99.4–99.95% in the stable region (cycles 60–400), for the heat-treated specimen [Source 12]
• Control with four-component systems: systems with four components made by removing Zn, Cu or Co from the five (medium entropy) showed different, rather unstable electrochemical behaviour. The systems without Mg and without Ni did not become single-phase even at much higher temperatures and were left out of the comparison. Without Zn, oxidation proceeds in two steps and, on Li extraction, the original rocksalt structure does not seem to be regained but to separate into different phases [Source 12]. The paper writes that the difference is “probably related to entropy stabilisation” [Source 12] (not a confirmed cause)

7. Making and measuring — milling, sintering, densification, identifying the phase

The “Example confirmed in primary sources” column is Sourced (statements in each paper; numbers refer to the references). The arrangement of the table is this article’s Commentary. The method for density and porosity is defined by ISO 18754:2020 (including the Archimedes method) [Source 20].

8. Separating entropy from “disorder”

Laying the reports side by side, the explanation of an improved property falls, material by material, into two kinds: stabilisation by entropy and the effect of disorder itself.

• The question of stabilisation: why does this composition become single-phase? Entropy, enthalpy, or kinetics (quenching)? Rost et al. showed entropy’s role with four kinds of evidence [Source 1], and Sarkar et al. say the questions about the role remain open [Source 2]
• The question of properties: why is a material that has become single-phase hard, insulating, or a good ion conductor? Toher et al. say disorder raises properties through solid-solution strengthening, lower lattice thermal conductivity and so on [Source 13]. The thermal conductivity in Wright et al. correlated with the size-disorder parameter [Source 9]

9. Limits, and what could not be confirmed

• Depth of checking of primary sources: the open-access bodies of Rost et al. (2015) and Sarkar et al. (2018) were checked. Most other papers were checked only to the level of their abstracts, and Jiang et al. (2018) only by title. For Sarkar et al. (2022), the abstract on a university’s institutional-repository page was checked
• Perovskite-type, high-entropy nitrides and other systems including rare earths: the content was not checked here. Catalysis, thermoelectrics, dielectrics and magnetism are outside this article
• Oxidation resistance, high-temperature strength, thermal-shock resistance: oxidation resistance as an ultra-high-temperature ceramic (only a preliminary assessment by Gild et al.), high-temperature strength and thermal shock were not checked in numbers
• Practical products, markets and prices: could not be confirmed in primary sources. Market-research estimates are not used
• Batteries: the battery values here are active-material capacities in a half cell; the energy density, safety and life of a full cell were not checked. This article is not advice on safety, medicine or investment
• Judging “entropy stabilisation”: this article lays out the confirmed evidence within what the papers state. It does not judge whether any individual material is “entropy-stabilised”
• Standards specific to them: no ISO, IEC, IEEE or JIS standard aimed at high-entropy ceramics could be confirmed (Section 10)

10. How to read evaluations and standards

Evaluation of high-entropy ceramics uses tests of flexural strength, hardness, fracture toughness, thermal diffusivity and conductivity, density and porosity, and thermal expansion. Papers also do phase identification (X-ray diffraction), local structure (such as EXAFS) and half-cell battery tests. What standards define is the method of each test; they do not define “high-entropy” or “entropy stabilisation”, or give pass criteria for a material’s performance. No ISO, IEC, IEEE or JIS standard aimed at high-entropy ceramics could be confirmed in this article.

Standard numbers and titles were checked on official ISO pages for ISO and on the JIS search of the Japanese Industrial Standards Committee (JISC) for JIS; JIS titles are our translation of the Japanese titles. For ASTM standards, the ASTM website was not opened; only the number and the stated use were checked in the body of peer-reviewed papers. The ASTM column gives no test content, conditions or acceptance criteria. The arrangement of the table is Our calculation.

Where each standard sits — international, national, trade body

• ISO is an international standard, JIS a national standard, and ASTM a trade standard issued by a US standards body. ISO 14704, JIS R 1601 and ASTM C1161 are all “flexural strength” standards, but their degree of agreement (identical, modified and so on) could not be confirmed because their texts were not checked
• ISO 14705 is current as the 2026 edition (4th edition, September 2026), and the 2016 edition is withdrawn. ISO 23146:2012 is to be revised and its use for Y-TZP is not recommended. ISO 18756 is the 2003 edition, confirmed. The same number can carry a different procedure in a different edition
• ISO standards for fracture toughness have separate numbers by method (SEPB, SEVNB, SCF). ISO 15732 states in its scope that fracture toughness values from other methods cannot be interchanged with its own and may not be interchangeable with each other [Source 16]

Cautions when reading

• A standard is a “test method” and does not guarantee a material’s performance. “A hardness to ISO 14705” is a value from that method, not a ranking of materials
• The measurement in a paper can differ from a standard. The hardness in the papers cited here is by nanoindentation [Sources 5, 6], a different method from the Vickers and Knoop hardness of ISO 14705
• There is no standard for judging “entropy stabilisation”. Read the checks a paper shows (reversibility, endotherm, control, local structure) paper by paper [Source 1]
• Evaluation of functions such as batteries, catalysis and dielectrics follows each paper’s conditions. No applicable standard could be confirmed within this article’s survey

11. Glossary

12. References (primary sources)

1. Rost C. M., Sachet E., Borman T., Moballegh A. et al. “Entropy-stabilized oxides”, Nat. Commun. 6, 8485 (2015), DOI 10.1038/ncomms9485 (open access, body checked) — doi.org/10.1038/ncomms9485
2. Sarkar A., Breitung B., Hahn H. “High entropy oxides: The role of entropy, enthalpy and synergy”, Scr. Mater. 187, 43–48 (2020), DOI 10.1016/j.scriptamat.2020.05.019 (abstract checked) — doi.org/10.1016/j.scriptamat.2020.05.019
3. Sarkar A., Eggert B., Witte R., Lill J. et al. “Comprehensive investigation of crystallographic, spin-electronic and magnetic structure of (Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)3O4: Unraveling the suppression of configuration entropy in high entropy oxides”, Acta Mater. 226, 117581 (2022), DOI 10.1016/j.actamat.2021.117581 (abstract checked on a university institutional-repository page) — doi.org/10.1016/j.actamat.2021.117581
4. Sarker P., Harrington T., Toher C., Oses C. et al. “High-entropy high-hardness metal carbides discovered by entropy descriptors”, Nat. Commun. 9, 4980 (2018), DOI 10.1038/s41467-018-07160-7 (open access, abstract checked) — doi.org/10.1038/s41467-018-07160-7
5. Castle E., Csanádi T., Grasso S., Dusza J. et al. “Processing and Properties of High-Entropy Ultra-High Temperature Carbides”, Sci. Rep. 8, 8609 (2018), DOI 10.1038/s41598-018-26827-1 (open access, abstract checked) — doi.org/10.1038/s41598-018-26827-1
6. Harrington T. J., Gild J., Sarker P., Toher C. et al. “Phase stability and mechanical properties of novel high entropy transition metal carbides”, Acta Mater. 166, 271–280 (2019), DOI 10.1016/j.actamat.2018.12.054 (abstract checked) — doi.org/10.1016/j.actamat.2018.12.054
7. Gild J., Zhang Y., Harrington T., Jiang S. et al. “High-Entropy Metal Diborides: A New Class of High-Entropy Materials and a New Type of Ultrahigh Temperature Ceramics”, Sci. Rep. 6, 37946 (2016), DOI 10.1038/srep37946 (open access, abstract checked) — doi.org/10.1038/srep37946
8. Gild J., Samiee M., Braun J. L., Harrington T. et al. “High-entropy fluorite oxides”, J. Eur. Ceram. Soc. 38, 3578–3584 (2018), DOI 10.1016/j.jeurceramsoc.2018.04.010 (abstract checked) — doi.org/10.1016/j.jeurceramsoc.2018.04.010
9. Wright A. J., Wang Q., Ko S.-T., Chung K. M. et al. “Size disorder as a descriptor for predicting reduced thermal conductivity in medium- and high-entropy pyrochlore oxides”, Scr. Mater. 181, 76–81 (2020), DOI 10.1016/j.scriptamat.2020.02.011 (abstract checked) — doi.org/10.1016/j.scriptamat.2020.02.011
10. Jiang S., Hu T., Gild J., Zhou N. et al. “A new class of high-entropy perovskite oxides”, Scr. Mater. 142, 116–120 (2018), DOI 10.1016/j.scriptamat.2017.08.040 (only the title checked) — doi.org/10.1016/j.scriptamat.2017.08.040
11. Bérardan D., Franger S., Meena A. K., Dragoe N. “Room temperature lithium superionic conductivity in high entropy oxides”, J. Mater. Chem. A 4, 9536–9541 (2016), DOI 10.1039/C6TA03249D (abstract checked) — doi.org/10.1039/c6ta03249d
12. Sarkar A., Velasco L., Wang D., Wang Q. et al. “High entropy oxides for reversible energy storage”, Nat. Commun. 9, 3400 (2018), DOI 10.1038/s41467-018-05774-5 (open access, body checked) — doi.org/10.1038/s41467-018-05774-5
13. Toher C., Oses C., Esters M., Hicks D. et al. “High-entropy ceramics: Propelling applications through disorder”, MRS Bull. 47, 194–202 (2022), DOI 10.1557/s43577-022-00281-x (abstract checked) — doi.org/10.1557/s43577-022-00281-x
14. International Organization for Standardization (ISO) ISO 14704:2016 “Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for flexural strength of monolithic ceramics at room temperature” (applies to grain size below 200 µm) — iso.org/standard/65411
15. International Organization for Standardization (ISO) ISO 14705:2026 “Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for hardness of monolithic ceramics at room temperature” (4th edition, published 2026-09; Vickers and Knoop; the previous ISO 14705:2016 is withdrawn) — iso.org/standard/85746
16. International Organization for Standardization (ISO) ISO 15732:2003 “Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for fracture toughness of monolithic ceramics at room temperature by single edge precracked beam (SEPB) method” — iso.org/standard/28366
17. International Organization for Standardization (ISO) ISO 23146:2012 “Fine ceramics (advanced ceramics, advanced technical ceramics) — Test methods for fracture toughness of monolithic ceramics — Single-edge V-notch beam (SEVNB) method” (to be revised; use for Y-TZP is not recommended) — iso.org/standard/62093
18. International Organization for Standardization (ISO) ISO 18756:2003 “Fine ceramics (advanced ceramics, advanced technical ceramics) — Determination of fracture toughness of monolithic ceramics at room temperature by the surface crack in flexure (SCF) method” (2003-12, confirmed) — iso.org/standard/31902
19. International Organization for Standardization (ISO) ISO 18755:2022 “Fine ceramics (advanced ceramics, advanced technical ceramics) — Determination of thermal diffusivity of monolithic ceramics by flash method” — iso.org/standard/81531
20. International Organization for Standardization (ISO) ISO 18754:2020 “Fine ceramics (advanced ceramics, advanced technical ceramics) — Determination of density and apparent porosity” — iso.org/standard/69745
21. International Organization for Standardization (ISO) ISO 20507:2022 “Fine ceramics (advanced ceramics, advanced technical ceramics) — Vocabulary” — iso.org/standard/74705
22. Japanese Industrial Standards Committee (JISC) JIS search “JIS R 1601 Testing method for flexural strength (modulus of rupture) of fine ceramics at room temperature” (title translated from the Japanese) — jisc.go.jp (R1601)
23. Japanese Industrial Standards Committee (JISC) JIS search “JIS R 1607 Testing methods for fracture toughness of fine ceramics at room temperature” (title translated from the Japanese) — jisc.go.jp (R1607)
24. Japanese Industrial Standards Committee (JISC) JIS search “JIS R 1610 Testing method for hardness of fine ceramics” (title translated from the Japanese) — jisc.go.jp (R1610)
25. Japanese Industrial Standards Committee (JISC) JIS search “JIS R 1611 Measurement methods of thermal diffusivity, specific heat capacity and thermal conductivity for fine ceramics by flash method” (title translated from the Japanese) — jisc.go.jp (R1611)
26. Japanese Industrial Standards Committee (JISC) JIS search “JIS R 1634 Test methods for density and open porosity of sintered fine ceramics” (title translated from the Japanese) — jisc.go.jp (R1634)
27. Japanese Industrial Standards Committee (JISC) JIS search “JIS R 1618 Measuring method of thermal expansion of fine ceramics by thermomechanical analysis” (title translated from the Japanese) — jisc.go.jp (R1618)
28. Public material used to confirm ASTM numbers and the uses stated for them (the ASTM website was not consulted): C1161 in Adv. Sci. 11, 2408277 (2024), DOI 10.1002/advs.202408277 (ASTM C1161 used as the standard method for flexural strength of advanced ceramics at ambient temperature) / C1327 in Nat. Commun. 17, 7513 (2026), DOI 10.1038/s41467-026-74043-7 (Vickers hardness of advanced ceramics measured to ASTM C1327) / C1421 in Nat. Commun. 17, 7494 (2026), DOI 10.1038/s41467-026-74505-y (fracture toughness measured by the SENB method to ASTM C1421-18) / E1461 in Sci. Rep. 16, 10739 (2026), DOI 10.1038/s41598-026-44244-7 (thermal conductivity obtained to ASTM E1461 from flash-method thermal diffusivity) — doi.org/10.1002/advs.202408277 (and others)

13. Claim-to-source audit

Last updated 10 October 2026. Sources are limited to primary material (peer-reviewed papers and standards-body pages). The bodies of Rost et al. (2015) and Sarkar et al. (2018) were checked; most other papers were checked only to the extent of their abstracts. Because the article includes structural readings and materials-design interpretations, those are marked as Commentary and kept separate from sourced fact. The content of perovskite-type oxides, other systems, numbers for oxidation resistance and high-temperature strength, practical products, prices and markets, full-cell performance, the judgement of whether an individual material is “entropy-stabilised”, and standards specific to high-entropy ceramics could not be confirmed and are not stated here. The figures are laboratory results with composition, route, density and test conditions fixed, and cannot be generalised to other materials or real use. All figures are explanatory concept graphics. Figs. 2, 3, 4 and 6 are vector drawings; Figs. 1 and 5 are AI-generated images, and none of them shows a real micrograph, experimental data or physical product.