|
| Design factors | Unit | Levels |
| 1 | 2 | 3 |
|
| Concentration of source of nickel (nickel sulfate solution) (A) | g/L | 20 | | 30 |
| Concentration of reducing agent (sodium hypophosphite solution) (B) | g/ L | 14 | | 20 |
| Concentration of source of tungsten (sodium tungstate) (C) | g/ L | 15 | | 25 |
| Annealing temperature (D) |
°C | 400 | | 600 |
|