Park M., Ju H., Oh J. et al. · Nature Communications · 2025 · 1316
Open a family to keep every result attached to its sample, method and conditions.
Paraphrased for this database from the authors’ stated interpretations — never quoted verbatim — and kept separate from reported measurements.
Ni-BAND gel memristors show humidity-dependent volatile analogue switching and synaptic potentiation/depression, attributed to proton-electron-coupled modification of Schottky barriers.
Caveat: Application results are from gel devices, not pristine thin-film transport devices; some conductance/current magnitudes are figure-axis estimates.
6 · Results · Fig. 6 · Linked to 5 structured results
XPS and PXRD support formation of Ni-BAND films without detectable nickel nitrate or precursor impurity.
Caveat: XPS detection limits and amorphous impurity sensitivity are not quantified.
3 · Results · Supplementary Fig. 5 · Linked to 3 structured results
The extensive H-bond network, hydrophilic NO3-/DMF/H2O components, and high-humidity multilayer water uptake support proton conduction in Ni-BAND.
Caveat: Authors also note weak H-bond fragments limit proton transport at low/intermediate humidity.
4 · Results · Fig. 3e; Fig. 4b · Linked to 5 structured results
Ni-BAND thin films exhibit preferred orientation with bpy-Ni-bpy planes tending to lie on the substrate surface.
2 · Results · Fig. 3f-h · Linked to 1 structured result
Humidity switches the dominant charge-carrier regime from electron-dominant transport in Phases I/II to proton-dominant transport in Phase III.
Caveat: Interpretation is model-dependent on TLM analysis of EIS spectra.
4 · Results · Fig. 4e-h · Linked to 3 structured results
Ni-BAND is a high mixed protonic-electronic conductor at room temperature, combining 0.24 S/cm electronic conductivity under dry/low-RH conditions and 0.09 S/cm proton conductivity under high humidity.
Caveat: Proton conductivity is an EIS/TLM estimate rather than a direct separated DC measurement.
2 · Introduction · Fig. 1 · Linked to 2 structured results
High electrical conductivity is attributed to n-type doping stabilised by the conjugated bpy-Ni-bpy backbone and enhanced by nitrate-vacancy structural disorder.
Caveat: Nitrate vacancy effects are supported by DFT modelling; defect concentration in experimental films/gels is not directly quantified.
6 · Results · Fig. 5 · Linked to 5 structured results
Names and aliases are kept exactly within the paper’s own identity model.
| Material | Composition | Structure context | Source |
|---|---|---|---|
| Ni-BAND | {[Ni(bpy)(H2O)2(DMF)2](NO3)2.2DMF}nNi(II) centres, six-coordinate · 4,4'-bipyridine (bpy); coordinated DMF; coordinated H2O; nitrate and non-coordinated DMF in H-bond network | 1D · PristineHydrogen-bonded one-dimensional coordination polymer with parallel bpy-Ni-bpy chains forming a supramolecular H-bond network; triclinic P-1 by SCXRD. | 2 · Results · Fig. 3; Supplementary Tables 1-4 |
| NO3- removed n-doped Ni-BAND computational model | Ni-BAND model with non-coordinating nitrate removedNi(II) · bpy, DMF, H2O; nitrate-vacancy model | 1D · Model SystemDefect model representing n-doped Ni-BAND induced by nitrate vacancies. | 7 · Fig. 5 caption · Fig. 5f |
| Ni-BAND precursor | [Ni(bpy)(H2O)2(NO3)2]nNi(II) · 4,4'-bipyridine | 1D · PristinePrecursor coordination polymer used to form Ni-BAND after dispersion in DMF. | 2 · Results · Fig. 2a |
| Pristine Ni-BAND computational model | {[Ni(bpy)(H2O)2(DMF)2](NO3)2.2DMF}nNi(II) · bpy, DMF, H2O, nitrate | 1D · Model SystemPeriodic DFT model optimised from the SCXRD structure. | 2 · Supplementary Note 1 · Fig. 5e |
Sample form, processing state and composition status define the context for measurements.
| Sample | Form and role | Processing and geometry | Source |
|---|---|---|---|
| Ni-BAND blue crystalsresearch_0561__mat__ni_band | Single Crystal · Target Sample · Pristine Framework | Crystals grown from filtered DMF dispersion, rinsed with MIBK and vacuum dried. | 8 · Methods · Fig. 2b,c |
| Ni-BAND gelresearch_0561__mat__ni_band | Thin Film · Target Sample · Pristine Framework | Dip-coated or drop-dried from 0.375 g/mL filtered DMF dispersion.glass or PET · thick, separable gel; 2 cm x 2 cm example | 9 · Methods · Fig. 2e; Fig. 6a |
| Ni-BAND gel memristor deviceresearch_0561__mat__ni_band | Electrode · Target Sample · Pristine Framework | Gel introduced onto masked bottom-electrode device; Ag electrodes prepared with conductive paste.glass substrate with Au bottom electrodes and Ag conductive-paste electrodes | 9 · Methods · Fig. 6b |
| Nitrate-vacancy n-doped Ni-BAND DFT modelresearch_0561__mat__ni_band_n_doped_model | Model · Model System · Model | NO3- removed defect model used to examine n-doping. | 2 · Supplementary Note 1 · Fig. 5f |
| Ni-BAND powder/crystal-derived solidresearch_0561__mat__ni_band | Powder · Target Sample · Pristine Framework | Solid Ni-BAND used for PXRD, BET and water-vapour adsorption. | 7 · Supplementary Figures · Supplementary Fig. 4; Supplementary Fig. 8 |
| Pristine Ni-BAND DFT modelresearch_0561__mat__ni_band_pristine_model | Model · Model System · Model | Periodic VASP model optimised from SCXRD structure. | 9 · Methods |
| Ni-BAND thin filmresearch_0561__mat__ni_band | Thin Film · Target Sample · Pristine Framework | Spin-coated from 0.1 g/mL DMF precursor dispersion after air-plasma substrate treatment.SiO2(300 nm)/Si, quartz, ITO glass, or PET · 300 nm | 2 · Results · Fig. 2d; Supplementary Fig. 1 |
| Ni-BAND thin-film Au-electrode deviceresearch_0561__mat__ni_band | Electrode · Target Sample · Pristine Framework | Au sputtered for 80 s through shadow mask on Ni-BAND thin film.SiO2/Si or quartz with sputtered Au electrodes · 300 nm film | 9 · Methods · Fig. 4a |
| Ni-BAND precursor precipitateresearch_0561__mat__ni_band_precursor | Powder · Unknown · Pristine Framework | Filtered and rinsed ethanol precipitate; stored dry. | 8 · Methods |