Dependence of Nucleation Field on the Size of Soft Phase in Magnetic Hard–Soft Exchange Coupling Nanocomposites
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear authors, your manuscript is interesting. The results shown can make a positive contribution to the development of the industry. But the motivation and novelty of the research are not clearly described. In my opinion, in order to improve the manuscript, it is advisable to take into account the following comments:
1. Please clearly define the purpose and novelty of your paper in Abstract.
2. 1. Introduction does not include the description of the purpose, as well.
3. I cannot agree with the term "epitaxial growth" (lines 99, 111, 117) in relation to a magnetron sputtering system. Epitaxy is a method used to grow or deposit monocrystalline films. Magnetron is commonly used to grow polycrystalline films of metals or their alloys.
4. Please describe the magnetron sputtering process in more detail in section 2. Experimental Details: how many magnetrons, chemical composition of the targets, argon pressure, current density, etc.
5. In Section 2. Experimental Details, it is desirable to briefly mention the design features of the magnetrons with ferromagnetic targets (Fe and Sm-Co) in your ultra-high vacuum magnetron sputtering machine.
6. If a Sm-Co alloy target is used for the deposition of the corresponding film, the manuscript should include a text explaining how the effect of preferential sputtering of samarium is taken into account. This effect is inevitable because the sputtering yields of samarium and cobalt differ by more than a factor of two.
7. Please describe in more detail the optimization process (see "...substrate via optimizing the sputtering fabrication parameters." line 118).
8. The reference list does not contain any publications on Sm-Co films of the last two years. Doesn't this mean that the topic has lost its relevance?
9. Reference 8 doesn’t include the year of publication.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis work is centered on synthesizing and analyzing Sm-Co/Fe bi-layer films, which show applications requiring magnetic hard-soft exchange coupling nanocomposites. The manuscript reveals an examination of how the nucleation field of the soft phase varies with its size, utilizing a fitting model in agreement with the data. Findings indicate the existence of a thin interfacial layer (approximately 4-6 nm) of softened hard magnetic phase that reverses alongside the soft phase under certain magnetic field conditions. This work provides an interesting understanding of magnetic reversal mechanisms in nanocomposites. Before further consideration, the following point should be solved:
1.The introduction is overly saturated with citations, which detracts from a focused presentation of the core problem and the proposed solution. The authors should consider refining this section to foreground their unique contribution more effectively. Additionally, it would be beneficial to outline the structure of the article at the end of the introduction to provide a roadmap for the reader, compensating for the current lack of a summarizing conclusion that could tie the study's objectives with its outcomes.
2. Section 2 must be split into "Materials", "Experimental Process", and Characterization Techniques. To further context, this section appears to provide a detailed account of the materials and methods sufficient for reproducibility. However, for complete reproducibility, one might expect additional details such as the sputtering parameters (e.g., power, deposition rate), the atmosphere composition, and more precise temperature control and measurements during the deposition process. Moreover, the specifics of the XRD and SQUID-VSM measurements (e.g., angles, temperature range, magnetic field range) would be necessary for another researcher to accurately replicate the study. In addition, why the information on the S1 and S2 points are moved to SI?
3. The authors have chosen to focus on temperature measurements at 25 K and 300 K, which likely represent significant points such as the room temperature and another relevant low-temperature state in their study. However, it is worth exploring if there might be notable phenomena occurring at intermediate temperatures. The behavior of magnetic materials can often exhibit critical changes at specific temperatures not captured by examining only these two points.
4. Can the authors provide morphological characterizations?
5. The article lacks of Conclusions section, then, expand the Discussions and separate them from Results.
6. Fig. 2, for a thorough discussion, one would analyze the peak widths (which can indicate crystallite size and microstrain), positions (which can relate to lattice constants and potential strain), and intensities (which can relate to texture and phase abundance).
7. The article would benefit from additional and proper characterization techniques to substantiate the reported findings more robustly. Incorporating a suite of complementary analytical methods would enhance the validity and depth of the results, allowing for a multi-faceted examination of the material properties. This could include but is not limited to, electron microscopy for microstructural analysis, magnetometry for magnetic property assessment, and spectroscopy for chemical state identification. The inclusion of these methods would provide a more holistic view of the material system studied and reinforce the conclusions drawn from the current data.
Comments on the Quality of English LanguageDouble-check sentence and paragraph connection, etc.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsMy comments on the authors' responses:
1. I agree.
2. I agree.
3. I agree.
4. I agree.
5. I disagree. When using a ferromagnetic target in a standard magnetron, there is a problem with the magnetic field. It is created by permanent magnets located in the cavity of the magnetron where the liquid that cools the target circulates. When sputtering a target of paramagnetic metal or alloy, the magnetron works steadily. If a ferromagnetic target is installed in such a design, it will close the magnetic field lines and the magnetron effect in the device will disappear. Such a magnetron will not work unless another source is provided to create a magnetic field near the target. Please, if you can, pay attention to this in your article.
6. I agree.
7. I agree.
8. I agree.
9. I agree.
Reviewer 2 Report
Comments and Suggestions for AuthorsThank you for providing the revised version after considering all points. I recommend the publication of the work.
