Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript by Ji-Han Kwak et al presents the results of a study of the characteristics and composition of the Fe-Ni Invar alloy fabricated by the electroplating method. It was investigating the effect on the properties of the electrodeposited Fe-Ni alloy by controlling the amount of SLS content, which acts as a surfactant. The composition homogeneity, microstructure, and surface defects of the electrodeposited Fe-Ni alloy were investigated. In my opinion, the results presented in the manuscript will be of interest to readers of Coatings. I propose publication of the manuscript, however, after revision.

- It is not clear to me how the thickness of the coatings was determined. It would be helpful to show typical roughness values.

- Figures 2 and 3 require improvement. Authors should add errors to the defined values.

- I don’t understand Fig. 3. I only see black rectangles.

- The authors should provide a clearer explanation of the effect of sodium lauryl sulfate on the uniformity of the resulting coatings.

Author Response

Thank you for the reviewer’s helpful comments, therefore we revised the contents carefully and sincerely response to each comment.  

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this study, the authors investigated how SLS added to electrodeposition acts as a surface-active agent to mitigate the difference in surface tension between the plating solution and the cathode. The results of this study will contribute to advances in display technology by providing insights that will help optimize the electro-deposition process, which is essential for producing high-resolution OLED displays. I read this paper with great interest. I would recommend publication of this paper. However, the authors need to address the following concerns

 

1) What does [ref] mean in lines 64 and 65?

 

2) What is the simulator in line 74? Explain in more detail.

 

3) Put the units on the horizontal axis in Figures 2 and 3.

 

4) It has been suggested that in electroplating, ligands in the complexes of the metal source remain on the metal surface and affect the surface free energy: https://doi.org/10.1021/acs.langmuir.1c00285

Are there any such concerns in this study?

Author Response

Thank you for the reviewer’s helpful comments, therefore we revised the contents carefully and sincerely response to each comment.  

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

In this manuscript, the authors studied the influence of sodium lauryl sulfate on Fe-Ni electrodeposition in order to enable the realization of masks for OLED manufacturing with improved resolution and thermal behaviour.

The majority of the references in the manuscript are from at least 10 years ago. This is not an issue in itself, but NiFe electrodeposition is an active topic with several recent reports that were not considered in this manuscript. A few examples are:

1. Kang, Na-Young, and Jae-Ho Lee. "Effects of Bath Composition and Current Density on the Electrodeposition Behavior of Fe–Ni Invar Alloy." Electronic Materials Letters (2023): 1-7

2. Lee, Myung Bok, Sung Hoo Ju, and Jae Woo Ahn. "High-Pixel-Density Fine Metal Mask Fabricated by Electroforming of Fe-Ni Alloy onto UV-nanoimprinted Resin Pattern on Si Substrate." Transactions on Electrical and Electronic Materials 24.5 (2023): 373-380.

3. Zubar, Tatiana I., et al. "Features of galvanostatic electrodeposition of NiFe films with composition gradient: Influence of substrate characteristics." Nanomaterials 12.17 (2022): 2926.

4. Tikhonov, R. D., et al. "Mechanical Stresses and Magnetic Properties of NiFe and CoNiFe Films Obtained by Electrochemical Deposition." Semiconductors 56.13 (2022): 431-436.

There are many other reports on the topic from 2010 to 2022 that should be used to properly summarize the state-of-the-art and contextualize the motivation and results of the current manuscript in a more comprehensive manner. In addition, previous literature about the influence of SLS on the electrodeposition of similar systems (i.e., Ni, CoNi, FeCo, etc.) were not reviewed.

Given the large amount of (recent) articles about NiFe electrodeposition and about the influence of SLS on Ni- and Fe-based alloy electroplating, the work reported in the authors' manuscript is not properly contextualized. Therefore, it is not possible to suitably assess the scientific contribution of their work.

Regarding the results reported in the manuscript, there are additional issues that should be addressed:

- Only a single bath composition was considered. Even if the concentration of iron and nickel salts (and maybe boric acid) are maintained constant, control experiments without saccharin should be performed. However, the ratio of Fe/Ni should be ideally varied in order to properly understand the influence of SLS in the electrodeposited film

- The influence of bath temperature and stirring rate were not considered

- Only two pH values (2.4, 2.8) were systematically studied. However, a larger window with more conditions is needed.

- Cyclic voltammogram studies (and/or other methods) for each composition should be provided so that the influence of SLS on the electrolyte can be better understood

- The current density window is too limited (8 to 16 mA/cm2)

- Potentiostatic deposition should also be performed

- Since the focus of the paper is the influence of SLS on NiFe electrodeposited materials, additional characterization and/or simulations are needed in order to correlate electrodeposition conditions and thin film properties

In summary, this manuscript reports on a topic of high technological relevance. However, additional experiments and literature review are needed before considering it for publication. Given the time needed for those tasks, I recommend the manuscript to be rejected in its current version.

Author Response

Thank you for the reviewer’s helpful comments, therefore we revised the contents carefully and sincerely response to each comment.  

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

I would like to thank the authors for addressing my previous comments.

Regarding the authors' response to Question 2, where they discussed the impact of temperature and stirring rate on Ni composition, they have chosen to keep these conditions constant to maintain a fixed Ni ratio. However, it is important to consider that temperature, stirring rate, and Ni ratio can collectively affect both the electrolyte and the electrodeposited films as a function of SLS concentration. If the main objective is to investigate the influence of SLS, it may not be advisable to disregard these factors in favor of maintaining a constant Ni concentration.

Furthermore, it is reasonable to expect that the pH range at which white rust or delamination may occur could vary depending on the deposition mode (i.e., pulsed, constant potential, constant current, etc.). This further highlights the importance of studying the effects of temperature, stirring rate, pH, and other variables.

In summary, the methodology employed in the manuscript seems to have over-constrained the system under investigation, making it challenging to draw broad conclusions about the impact of SLS.

As previously mentioned, the topic under study is technologically relevant. However, it is my opinion that the current version lacks the comprehensiveness needed for publication. Since the second version of the manuscript remains largely unchanged, I maintain my recommendation of not pursuing publication of the manuscript at this time.

Author Response

We revised carefully the whole manuscript, strengthened the text highlighted in red, and added the CTE values for having the degree of completion.