Thermal Hysteresis in Melting–Solidification of Nanoparticles
Round 1
Reviewer 1 Report
Ms. Ref. No.: applsci-212205
Title: Thermal Hysteresis in Melting-Solidification of Nanoparticles
Article type: Full Length Article
Reviewer's Comments:
1) Line 6; Is it common to have another subtitle “Developing understanding of thermal hysteresis in melting-solidification of nanoparticles” for abstract? The subtitle is slightly different from the title of this manuscript.
2) The authors did not explain or highlight the reason of carrying out this research work. What is the difference between current research work with other published research work in this field?
3) There are many equation being presented in the section of introduction but no references are being provided.
4) Similarly to the section of results and discussion, the authors did not provide references for equation 5 until equation 11.
5) There are only one figure being presented in this work and it shows that further investigation is needed.
Author Response
I am grateful to the Reviewer for the comments, which definitely resulted in an improved presentation of the research.
Comment1: Line 6; Is it common to have another subtitle “Developing understanding of thermal hysteresis in melting-solidification of nanoparticles” for abstract? The subtitle is slightly different from the title of this manuscript.
A: This line isn’t compulsory, and to avoid any confusion it has been deleted.
Comment2: The authors did not explain or highlight the reason of carrying out this research work. What is the difference between current research work with other published research work in this field?
A: An extra sentence is added in the Introduction (lines 54-55) to summarise the state of the art regarding thermal hysteresis in nanoparticles.
Comment3: There are many equation being presented in the section of introduction but no references are being provided.
Eq. (1) is related to Ref [9]. Eqs (2)-(3) are presented for illustrating the possible steps of deriving the commonly used dependence of melting temperature on the nanoparticle radius. This is useful because simultaneously we present an expression for the entropy change upon melting or solidification of nanoparticle, which is used in deriving Eq. (7). Eq. (4) is a useful new form of the main equation of the classical nucleation theory (CNT) referred to in Refs [10-11].
Comment4: Similarly to the section of results and discussion, the authors did not provide references for equation 5 until equation 11.
Equation (5) is an original one and is the key equation of the analysis. Eqs (6)-(8) are convenient versions of the typical equations within CNT (an extra indication of the fact that the analysis is carried out within the CNT is added in lines 65-66), which is referred to in [10-11]. Eqs (9)-(11) are the original ones.
Comment5: There are only one figure being presented in this work and it shows that further investigation is needed.
In fact, there are two figures, but I totally agree with the Reviewer that a further investigation in this direction would be useful, as the presented approach provides a qualitative understanding of this important and quite complicated problem.
Reviewer 2 Report
Authors implemented a generic approach based on the classical nucleation theory and define the thermal hysteresis for a nanoparticle. This approach is effective and interesting. The following suggestions are intended to enhance the manuscript quality, although they may not be sufficient for publication.
(1) Some factors mainly affect the melting Tm and solidification Ts temperature of nanoparticles, which should be listed and discussed.
(2) The parameter value δ0 of simple metals is close to 0.17 (Line 97-98), whether this δ0 value apply to metallic alloy mentioned in line 103-104 should be discussed.
(3) Whether the general approach established by the author is applicable to alloys should be discussed.
Author Response
I am very grateful to the Reviewer for very thoughtful and useful comments.
(1) Some factors mainly affect the melting Tm and solidification Ts temperature of nanoparticles, which should be listed and discussed.
A: An extra paragraph is added to emphasize the role of the factors affecting the melting and solidification temperatures – see lines 60-63.
(2) The parameter value δ0 of simple metals is close to 0.17 (Line 97-98), whether this δ0 value apply to metallic alloy mentioned in line 103-104 should be discussed.
A: In general, the value of δ0 can be somewhat different, i.e. it is about 0.1 for Sn-Ag-Cu alloys. The qualitative behavior of (R) in this case remains very simlar. Corresponding sentense is added in the manuscript (lines 102-104) and an extra reference [25].
(3) Whether the general approach established by the author is applicable to alloys should be discussed.
A: An extra paragraph at the end of the Results and Discussion section is added to address the issue.
Round 2
Reviewer 1 Report
Although the authors have done some corrections based on the reviewer's comment, the manuscript cannot be considered for publication due to the lacking of reported data from this simulation work. I would highly recommend the authors to present more results. Therefore, I need to reject this manuscript from being published in Applied Sciences.
Author Response
I am grateful to the reviewer for the suggestion to verify the presented model against experimental data. Unfortunately there is virtually no reliable data on solidification point of metallic nanoparticles available in literature. Therefore I present the data from numerical experiment (molecular dynamics simulation) for Pd nanoparticles to compare with the model - see the insert in Fig.2 of the revised manuscript. The corresponding reference [26] is also added. It can be seen that the presented "numerical experimental" data agree rather well with the model calculations for palladium nanoparticles.
I hope this answers the Reviewer's comment.
