Formation of Metallic Ag on AgBr by Femtosecond Laser Irradiation

Round 1

Reviewer 1 Report

The manuscript entitled "Formation of Metallic Ag on AgBr by Femtosecond Laser  Irradiation" by Cabral and his co-workers investigated the effects of femtosecond laser irradiation on AgBr with the aid of theoretical simulations. The work addresses the simulations within two-temperature model. This is generating a lot of interest in the physics/chemistry community and certainly providing a thorough understanding of the laser irradiation process is important and will generate attention in these communities. I just have a small question about the MD simulation time: Fig. 5 shows the MD simulation results for 5 ps. However, the authors told us in section 2 that the MD simulations were performed for 0.5 ps. It should be carefully explained.

Author Response

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Report of the First Reviewer

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Reviewer 1: The manuscript entitled “Formation of Metallic Ag on AgBr by Femtosecond Laser Irradiation” by Cabral and his co-workers investigated the effects of femtosecond laser irradiation on AgBr with the aid of theoretical simulations. The work addresses the simulations within two-temperature model. This is generating a lot of interest in the physics/chemistry community and certainly providing a thorough understanding of the laser irradiation process is important and will generate attention in these communities.

Authors: We thank the Reviewer for considering our manuscript for publication.

Reviewer 1: I just have a small question about the MD simulation time: Fig. 5 shows the MD simulation results for 5 ps. However, the authors told us in section 2 that the MD simulations were performed for 0.5 ps. It should be carefully explained.

Authors: We thank the Reviewer for this comment. In the revised version of the manuscript, we corrected this typo. The correct simulation time is 5.0 ps.

Reviewer 2 Report

The submitted manuscript is an example of well planned and designed scientific work. The studies of structural changes caused by the laser irradiation of materials are very important nowadays. Silver bromide (AgBr) is a good example of such interesting material. The used approach utilizing ab initio molecular dynamics simulations and periodic boundary conditions is correct. The most important result, in my opinion, is the formation of Ag clusters. I have therefore one question. The maximum time of the simulation was 5ps and the model consisted of 64 atoms in total. What could happen if we extend the time of simulation? Can we observe some symmetry in the clusters? formation of square, pentagons etc. ?

Author Response

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Report of the Second Reviewer

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Reviewer 2: The submitted manuscript is an example of well planned and designed scientific work. The studies of structural changes caused by the laser irradiation of materials are very important nowadays. Silver bromide (AgBr) is a good example of such interesting material. The used approach utilizing ab initio molecular dynamics simulations and periodic boundary conditions is correct.

Authors: We thank the Reviewer for considering our manuscript for publication.

Reviewer 2: The most important result, in my opinion, is the formation of Ag clusters.

Authors: We thank the Reviewer for highlighting this point.

Reviewer 2: I have therefore one question. The maximum time of the simulation was 5.0 ps and the model consisted of 64 atoms in total. What could happen if we extend the time of simulation?

Authors: The simulation time of 5.0 ps and electronic excitation of 2.0 eV is enough to observe the diffusion (Fig. 4) of silver atoms in the heated lattice (Fig. 5 of main text). We extended the simulation time for AgBr up to 10.0 ps for an electronic excitation of 2.0 eV. The obtained results follow the same trends as presented at 5.0 ps. This fact is now remarked in the revised version of the manuscript (See paragraph 02, page 08).

Sentence included: “The simulation time for AgBr was extended to 10.0 ps for an electronic excitation of 2.0 eV and the results obtained follow the same trends presented at 5.0 ps.”

Reviewer 2: Can we observe some symmetry in the clusters? formation of square, pentagons etc. ?

Authors: Within the two-temperature model, we can observe symmetry in the silver clusters. Therefore, to highlight this point, a new sentence in the revised information is now included (see paragraph 02, page 08).

Sentence included: “In the silver diffusion process, the Ag clusters formed present different types of symmetry, which depend on the simulation time and the intensity of the electronic excitation.”