Relationship of Metallophilic Interactions with Structural and Mechanical Properties of (1−x) (0.73GeSe₂-0.27Sb₂Se₃)-xAg₂Se Glasses

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Author：

1.Although the paper systematically explores the relationship between Ag-Ag interactions and plasticity enhancement, its innovative exposition is still insufficient. It is recommended to clearly point out the unique aspects of this study compared to previous work on Ag-based chalcogenides (such as Ag₂S-GeS₂, Ag₂Se-As₂Se₃, etc.).

 

2.In several figures (such as Fig. 2, Fig. 3, and Fig. 6), the sample x-values ​​are only mentioned in the figure titles, but the curves do not directly label the corresponding samples within the figures, and the vertical axis lacks unit information. It is recommended to add complete legends and coordinate descriptions to enable readers to accurately distinguish the results for each sample.

 

3.Optimize the presentation and explanation of specialized formulas. In the summary, expressions like the "Kohlrausch function" and the "plasticity calculation formula" are provided only as mathematical expressions without (plain-language) explanations of the parameters, making them difficult for non-specialist readers to understand. It is recommended to add parenthetical annotations after the formulas.

 

4. Incorporate more relevant literature to substantiate the conclusions.

 

5. Clarify the optimal range of Ag₂Se addition ratio and its applicable scenarios

The current study only presents the overall trend between Ag₂Se content (0~45 mol.%) and properties, but fails to identify the optimal addition ratio that balances plasticity enhancement and structural stability. It is recommended to supplement data on the long-term mechanical stability (e.g., fatigue life after cyclic deformation) and thermal stability (e.g., plasticity retention rate at high temperatures) of glasses with different Ag₂Se contents, clarify the optimal range (e.g., whether 40 mol.% in the paper is the best value for balancing plasticity and stability), and explain the practical adaptability of this ratio in combination with flexible electronics application scenarios.

 

6. Supplement direct characterization evidence for Ag-Ag metallophilic interactions

Currently, the study indirectly infers the existence and role of Ag-Ag bonds through XRD and NMR, lacking direct characterization support. It is suggested to add X-ray Photoelectron Spectroscopy (XPS) to characterize changes in the electronic state of Ag, or extend Extended X-ray Absorption Fine Structure (EXAFS) analysis to investigate the local coordination environment of Ag. This will directly confirm the formation, bond energy, and distribution characteristics of Ag-Ag bonds, enhance the persuasiveness of the conclusions, and make up for the gap with previous studies on Ag₂S-GeS₂ systems that relied solely on indirect evidence.

 

7. Improve the cross-validation logic of different characterization results

The correlation analysis between XRD (network structure changes), NMR (atomic coordination environment), and mechanical properties (stress relaxation, plasticity) in the paper is relatively scattered, failing to form a closed-loop verification. It is recommended to add a dedicated section or figures to systematically sort out the logical chain of "Ag₂Se addition → Ag-Ag bond formation → increased glass network mobility → changed stress relaxation mechanism → enhanced plasticity". Through mutual confirmation of multi-characterization data (e.g., the correspondence between the Ge-Se-Ag structure revealed by NMR and the disappearance of FSDP in XRD), the rigor of the argumentation is strengthened.

 

8. Supplement practical application performance verification of the glass system

The study focuses on the basic correlation between structure and mechanical properties, but lacks verification of core functional properties required for flexible electronics. It is recommended to supplement data such as ionic conductivity, optical transmittance (adapting to optoelectronic devices), and processing performance (e.g., feasibility of thin-film preparation, compatibility with flexible substrates) of the glass system. This will illustrate its potential application advantages in scenarios such as flexible sensors and flexible energy storage devices, connect basic research with practical applications, and enhance the practical value of the study.

Author Response

Attached please find our responses to reviewer 1 and reviewer 2

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript entitled “Relationship of metallophilic interactions with structural and mechanical properties of (1-x)(0,27Sb2Se3-0,73GeSe2)-xAg2Se glasses” (ID compounds‑3997988se) investigates the relationship between Ag2Se content and the Ge–Sb–Se chalcogenide system, with a thorough structural characterization by XRD and NMR. The authors present and analyse the primary data in detail. The manuscript is clearly written, understandable, and suitable in scope for Compounds.

I have only a few comments:

1. If I correctly understand the experimental section (lines 95–96), the glasses were analysed in the virgin (non‑annealed) state. How would annealing (tempering) affect the results, and would it not be preferable to study annealed glasses? In my view annealed samples are more relevant to applications in flexible electronics (see lines 23–25).

2. Please add comparative values of mechanical stress relaxation for alternative materials relevant for flexible electronics.

3. Figure 4: a formal typo — the values 0,0; 0,2; and 0,4 in the legend should use a decimal point (0.0; 0.2; 0.4).

4. The study relies on averaging techniques with limited local resolution, namely X‑ray diffraction and NMR. The authors do not appear to discuss whether and how such methods can detect phase separation, which is known to occur in Ag‑rich chalcogenide glasses at both the nano‑ and micro‑scale (e.g., DOI: 10.1016/j.jnoncrysol.2009.04.067; 10.1016/j.jnoncrysol.2006.09.065; 10.1016/j.jnoncrysol.2018.07.046). Would the phase separation scenarios reported in the literature be observable with the applied techniques?

5. Page 10, line 255: the authors mention changes in Se–Se bonding concentration with Ag content. Please comment on this observation in the context of bond‑statistical models versus bond‑energy‑based approaches (see DOI 10.1016/S0022‑3697(00)00026‑3). How does the observed trend relate to a purely statistical distribution of bonds compared to preferential bond formation driven by differing bond enthalpies?

6. Please consider the order in which the chemical composition of glass is written. I more often meet the order GeSe2-Sb2Se3 than the order used in the paper, Sb2Se3-GeSe2.

These are minor comments on an otherwise well‑executed experimental study with excellent data analysis and presentation.

Author Response

Attached please find our responses to reviewer 2

Author Response File: Author Response.pdf