DOI: 10.34810/data2743
title: Replication Data for: Smart design of porous Ni and Ni–W films with tunable mechanical and magnetic performance

description: Experimental raw data for all figures presented in the paper “Smart design of porous Ni and Ni–W films with tunable mechanical and magnetic performance” are provided. The data were used to investigate the influence of tungsten content and porosity on the mechanical, magnetic, and structural properties of electrodeposited Ni and Ni–W films. Dense and porous samples were fabricated using colloidal crystal templates composed of 20 and 200 nm polystyrene spheres. The experimental dataset includes SEM and AFM micrographs (Figure 1), GIXRD diffraction patterns and Rietveld refinement parameters (Figure 2 and Table 1), nanoindentation load–depth curves and mechanical results (Figure 3 and Table 2), VSM hysteresis and FORC measurements (Figures 4–5), magnetization versus temperature curves (Figure 6), and thermal stability analyses obtained by FESEM after successive annealing steps (Figure 7). The complete dataset supports the discussion of how tungsten alloying and porosity affect mechanical hardness, elastic modulus, saturation magnetization, Curie temperature, and morphological stability of the Ni–W coatings.
description: METHODOLOGICAL INFORMATION


1. Description of methods used for collection-generation of data: 
This dataset contains the synthesis and characterization data of Ni and Ni–W films electrodeposited using a double-jacketed, three-electrode cell coupled to a Metrohm Autolab PGSTAT302N potentiostat/galvanostat. A platinum wire served as the counter electrode (CE), and a double-junction Ag|AgCl (3 M KCl) reference electrode (Metrohm AG) with an outer 1 M Na₂SO₄ solution was used as the reference electrode (RE).

Dense films were deposited galvanostatically at a constant potential of −1.2 V vs. Ag|AgCl (3 M KCl) for 30 min from a gluconate-based electrolyte containing 0.11 M NiSO₄·7H₂O, 0.5 M sodium gluconate (NaC₆H₁₁O₇), and 0.65 M H₃BO₃, adjusted to pH 5.0. For Ni–W co-deposition, 0.05 M Na₂WO₄·2H₂O was added to the electrolyte. The working electrodes (WE) were Ti/Au-sputtered silicon (111) substrates (exposed area: 1 cm²), where Ti (10 nm) served as an adhesion layer and Au (90 nm) ensured electrical conductivity.

Porous Ni and Ni–W films were fabricated by colloidal crystal templating using the same electrolyte. A droplet of a commercial aqueous suspension of polystyrene (PS) spheres—either 20 nm (1 wt%, Thermo Scientific) or 200 nm (2.5 wt%, Polysciences)—was deposited on the Si/Ti/Au substrate. Two drops of Milli-Q water were added to promote uniform spreading, followed by solvent evaporation on a hot plate at 40 °C to facilitate PS self-assembly. Electrodeposition was then carried out on the PS-templated substrates at 25 °C under −1.2 V vs. Ag|AgCl (3 M KCl) for 10 min, repeated three times to reach a total deposition time of 30 min and a film thickness of approximately 1.5 µm, comparable to that of dense samples.

After deposition, PS spheres were removed by immersion in tetrahydrofuran (THF) for one week. The final film thickness was verified by mechanical profilometry (KLA Tencor P-15). 

After synthesis, the film morphology was examined by scanning electron microscopy (SEM) using a field-emission microscope to assess surface and cross-sectional features (Fig. 1). Grazing-incidence X-ray diffraction (GIXRD) measurements were subsequently performed to determine the crystallographic structure and phase composition of the deposits (Fig. 2).

The mechanical properties of the Ni and Ni–W films were evaluated by nanoindentation using a maximum indentation load of 1.5 mN, ensuring that substrate effects were negligible. The indentation data were analyzed following the Oliver and Pharr method, yielding the hardness (H) and Young’s modulus (E) of the samples (Fig. 3). Results for all films with a thickness of ≥ 1.5 µm are summarized in Table 2.

To study the magnetic behavior, replicated samples were prepared and analyzed using a vibrating sample magnetometer (VSM). Hysteresis loops and derived parameters such as coercivity, remanence, and saturation magnetization are shown in Figs. 4–6.

Finally, the thermal stability of the electrodeposited films was investigated by monitoring morphological evolution under controlled annealing conditions. Samples were heated under an inert Ar atmosphere from 298 K to 800 K at a constant heating rate of 5 K min⁻¹. At each target temperature (400, 500, 600, 700, and 800 K), the films were held isothermally for 1 min, then cooled to room temperature. After each annealing step, the surface morphology was characterized by FESEM (FEI Magellan microscope) to identify temperature-induced structural changes(Fig.7).


2. Methods for processing the data: 
N/A


3. Instrument- or software- specific information needed to interpret the data:
SEM: Zeiss Merlin with InLens detector/ FESEM using a FEI Magellan microscope
XRD: Malvern-PANalytical X’pert Pro diffractometer with Cu Kα radiation
Nanoindenter: Anton Paar NHT2 nanoindenter equipped with a Berkovich pyramidal-shaped diamond tip
VSM:The 8600 Series VSM Lake Shore


4. Instruments, calibration and standards information:
N/A


5. Environmental or experimental conditions:
Atmospheric influences


6. Quality-assurance procedures performed on the data:
N/A
description: Zeiss Merlin with InLens detector/ FESEM using a FEI Magellan microscope, null
description: Malvern-PANalytical X’pert Pro diffractometer with Cu Kα radiation, null
description: Anton Paar NHT2 nanoindenter equipped with a Berkovich pyramidal-shaped diamond tip, null
description: The 8600 Series VSM Lake Shore, null