Nanometers-Thick Ferromagnetic Surface Produced by Laser Cutting of Diamond

Round 1

Reviewer 1 Report

This paper condensates noticeable efforts on interesting fabrication techniques and samples measurements/characterisation. The results are rather interesting both for condensed matter physics, material science, and nanotechnology.

This is a well written and interesting paper. I just recommend proof editing.

Author Response

(1) Reviewer #1 wrote

 

„This paper condensates noticeable efforts on interesting fabrication techniques and samples measurements/characterisation. The results are rather interesting both for condensed matter physics, material science, and nanotechnology.

This is a well written and interesting paper. I just recommend proof editing.”

Reply: We thank the reviewer for the positive comment on our MS.

Reviewer 2 Report

The paper submitted by Annette Setzer. et. al describes the “Nanometers-thick Ferromagnetic Surface Produced by Laser Cutting of Diamond”. This work is quite interesting from a technological point of view. I recommended a minor revision of the manuscript. Before accepting the manuscript author should carry out the below comments and corrections:

 

1. In the introduction (page 2 lines 35-47) part, the author confused the content, please rewrite this part.  
2. The author should provide the previous literature survey discussion in the introduction part.
3. In the Results and Discussion Section, the authors should provide reasonable and convincing evidence to explain each experiment phenomena rather than a simple inference or results description.
4. Figures quality is poor. The author should improve the quality and format of the images.
5. The author mentioned maximum thickness of the magnetic layer is 20 nm. How the author measured magnetic layer thickness in the paper. Please provide a detailed analysis.

 

Author Response

(2) Reviewer #2 wrote

„The paper submitted by Annette Setzer. et. al describes the “Nanometers-thick Ferromagnetic Surface Produced by Laser Cutting of Diamond”. This work is quite interesting from a technological point of view. I recommended a minor revision of the manuscript. Before accepting the manuscript author should carry out the below comments and corrections:

1. In the introduction (page 2 lines 35-47) part, the author confused the content, please rewrite this part.“

Reply:

We thank the reviewer for the comment. We have rewritten the whole paragraph and removed or replaced some references. All the revised/corrected new paragraphs are in red color.

1. The author should provide the previous literature survey discussion in the introduction part.

The new paragraph in the introduction includes the literature survey we had in the last section of the original MS, which is now removed at that section.

1. In the Results and Discussion Section, the authors should provide reasonable and convincing evidence to explain each experiment phenomena rather than a simple inference or results description.

We thank the reviewer for the comment. We have rewritten the presentation and discussion of the results. We believe that the evidence provided by the magnetization data is convincing. From one side, it clearly shows a ferromagnetic order after laser treatment. On the other side, the vanishing of the ferromagnetic signals after chemical etching and heat treatment clearly indicate that those signals are related to the surface near graphitic-like region. From previous experimental and theoretical work, we know that ferromagnetic order can be trigger in graphite via defects (through ion irradiation or hydrogenation), the main origin for the observed phenomena is at the graphitic-like surface layer produced by the laser.

1. Figures quality is poor. The author should improve the quality and format of the images.

Indeed, the quality of compiled figures is very bad. Our figures have a much better resolution and quality than the one we obtained after the compilation of the journal latex file. We will inform the editor on this problem. The published papers in the journal, however, show a clearly better resolution. We speculate that this low quality is intended to decrease the memory size of the submitted manuscripts in the review process.

1. The author mentioned maximum thickness of the magnetic layer is 20 nm. How the author measured magnetic layer thickness in the paper. Please provide a detailed analysis.

We thank the reviewer for all the comments. The information on the estimate of 20nm thick surface layer is included in page 3, including two more references. We would like to note the reviewer the following: Theoretically, it is highly improbable that a ferromagnet exists with a Curie temperature clearly above 300K and a magnetization at saturation below ~ 10 emu/g. The values of the magnetization at saturation one finds in the literature of non-homogeneous ferromagnets, as those with defect-induced magnetic order, are in general misleading (too small) because of the assumption that the whole measured mass is ferromagnetic. Only in a very few publications the effective ferromagnetic mass has been quantified and in this case the magnetization values of magnetic graphite are between 20 and 40 emu/g, values compatible with the Curie temperature above 300K. We have included a few new citations in the revised MS.  

Reviewer 3 Report

The authors demonstrate that cutting diamond crystals with a laser (532 nm wavelength, 0.5 mJ energy, 200 ns pulse duration at 15 kHz) produces a < 20 nm thick surface layer with magnetic order at room temperature.

These results are very impressive.

Thereby, I recommend this manuscript for publication.

Author Response

(3) Reviewer #3 wrote

 

“The authors demonstrate that cutting diamond crystals with a laser (532 nm wavelength, 0.5 mJ energy, 200 ns pulse duration at 15 kHz) produces a < 20 nm thick surface layer with magnetic order at room temperature.

These results are very impressive.

Thereby, I recommend this manuscript for publication.”

We thank the reviewer for the positive comment on our MS.

 

Reviewer 4 Report

The present work studied the robust ferromagnetism at the laser-cutting-treated diamond surface depending on orientation. The results are interesting and may pave the way to create ferromagnetic spots at these kinds of treated diamond surfaces. Before acceptance, minor revision is needed. The authors indicated a ~20 nm thick surface layer with magnetic order produced during the laser-cutting process, but no evidence was provided. Furthermore, how many repeated times for the experimental data obtained in Fig. 5. Error bar should be added. 

Author Response

(4) Reviewer #4 wrote

“The present work studied the robust ferromagnetism at the laser-cutting-treated diamond surface depending on orientation. The results are interesting and may pave the way to create ferromagnetic spots at these kinds of treated diamond surfaces. Before acceptance, minor revision is needed. The authors indicated a ~20 nm thick surface layer with magnetic order produced during the laser-cutting process, but no evidence was provided. Furthermore, how many repeated times for the experimental data obtained in Fig. 5. Error bar should be added.”

 

We thank the reviewer for all the comments. The corresponding error bars were drawn in Fig.5.

The information on the estimate of 20nm thick surface layer is included in page 3, including two more references. We would like to note the reviewer the following: Theoretically, it is highly improbable that a ferromagnet exists with a Curie temperature clearly above 300K and a magnetization at saturation below ~ 10 emu/g. The values of the magnetization at saturation one finds in the literature of non-homogeneous ferromagnets, as those with defect-induced magnetic order, are in general misleading (too small) because of the assumption that the whole measured mass is ferromagnetic. Only in a very few publications the effective ferromagnetic mass has been quantified and in this case the magnetization values of magnetic graphite are between 20 and 40 emu/g, values compatible with the Curie temperature above 300K. We have included a few new citations in the revised MS.

Reviewer 5 Report

The manuscript entitled “Nanometers-thick Ferromagnetic Surface Produced by Laser Cutting of Diamond” deals with ferromagnetic order in thick graphitic layers created on diamond surface by  a laser's cutting off. Readers can be interested in  the article subject as reported results are unique, and research is  well-designed.   In my opinion, however, it can be published after major revision. 
Sentences between lines 51 and 55 fit better to the conclusion than the introduction subsection, where set goals need be formed. 
Sentences between lines 94 and 96, it is not clear when diamond samples had been introduced to acid's mixture after heating process or just  before? 
Please classify the nitrogen  complexes. They have been labeled as A, B and C. But in the literature they are not names of nitrogen complexes. These complexes are distinguishable by the authors, however, not correctly classify. 
line 143 wrong table reference.  
In my experience, it is a rare case when a peak at 1430 cm-1 is observed in Raman spectra. It is not clear it was on natural or CVD sample. 
In line 105 and 106 there are some percentages numbers. To what they are referring.  
In line 201 should be these four samples.
In Figure 6 there cannot be find results for 0.02 T.
In line 218 probably should be  orientational dependence.
In line 220, does it mean that  the superconducting solenoid contains some ferromagnetic core, as there is the hysteresis?
In lines 229 and 230, there is an unclear sentence. 
In lines 267 and 267 there is an unclear sentence.
In my opinion, a general remark to the conclusion subsection is that some sentences can be moved to the introduction section. 

Author Response

(5) Reviewer #5 wrote

“The manuscript entitled “Nanometers-thick Ferromagnetic Surface Produced by Laser Cutting of Diamond” deals with ferromagnetic order in thick graphitic layers created on diamond surface by a laser's cutting off. Readers can be interested in the article subject as reported results are unique, and research is well-designed. In my opinion, however, it can be published after major revision.

Sentences between lines 51 and 55 fit better to the conclusion than the introduction subsection, where set goals need be formed.”

 

We agree with the reviewer. We have shifted these sentences to the conclusion. All revised/corrected paragraphs are in red.

 

“Sentences between lines 94 and 96, it is not clear when diamond samples had been introduced to acid's mixture after heating process or just before?”

 

The chemical etching was done after the laser treatment. The confusion is due to the

sentence in the lines 96 and 97. A similar procedure is used to clean diamond from surface contaminants. We have simple deleted this sentence in the revised version.

 

“Please classify the nitrogen complexes. They have been labeled as A, B and C. But in the literature they are not names of nitrogen complexes. These complexes are distinguishable by the authors, however, not correctly classify.”

 

It is perhaps a misunderstanding. We did not mention nitrogen complexes but C-H complexes that in the literature are taken as possible origin for localized magnetic moment in the graphite structure. In any case we thank the reviewer for the comment. We have included in the revised version the meaning of the A-C nitrogen-related defects in the diamond structure in the text of page 3 (in red).

 

“line 143 wrong table reference.”

 

Thanks. It is corrected.

 

“In my experience, it is a rare case when a peak at 1430 cm-1 is observed in Raman spectra. It is not clear it was on natural or CVD sample.”

 

In the corresponding figure caption as well as in the text it is written “CVD sample #1b”.

 

“In line 105 and 106 there are some percentages numbers. To what they are referring.”

 

It is now clarified.

 

In line 201 should be these four samples.

 

Corrected.

 

In Figure 6 there cannot be find results for 0.02 T.

 

Corrected.

 

In line 218 probably should be orientational dependence.

 

Corrected.

 

 

In line 220, does it mean that the superconducting solenoid contains some ferromagnetic core, as there is the hysteresis?

 

Either it is due to some ferromagnetic parts and/or to the pinning of vortices at the solenoid superconducting wires.

 

In lines 229 and 230, there is an unclear sentence.

 

Corrected.

 

In lines 267 and 267 there is an unclear sentence.

 

Corrected.

In my opinion, a general remark to the conclusion subsection is that some sentences can be moved to the introduction section.”

Thanks, it is done.

Round 2

Reviewer 5 Report

After reading authors answers and reviewing introduced corrections, I agree on publication of the article.