Abnormal Domain Growth during Polarization Reversal in Lithium Niobate Crystal Modified by Proton Exchange

Round 1

Reviewer 1 Report

The paper is on abnormal domain growth in lithium nobiate crystal. The study is weel presented and I have only few remarks:

- In fig. 3, please give the interval time and the scale in all figures.

-In equation (1) and (4), what is the difference between the total length of stripe domains L and the domain length l? It is not well explained.

- The stripe domain was assumed to be proportional to the field excess. Is it similar to the Rayleigh law used for domain wall motions?

- Different fit parameters have beenfound on page 6. Can you compare them to the litterature?

There is 15 publications related to V.Ya. Shur. (44%). Please reduce the self-citations.

 

Author Response

The paper is on abnormal domain growth in lithium niobate crystal. The study is well presented and I have only few remarks:

- In fig. 3, please give the interval time and the scale in all figures.

Response:

We have given the time intervals and the scales in all figures of fig. 3.

-In equation (1) and (4), what is the difference between the total length of stripe domains L and the domain length l? It is not well explained.

Response:

The domain length l is a length of one stripe domain, while L is a total length of all stripe domains. We have rewritten the sentence before eq. (4) to clarify this point:

Page 5, Line 153:

Before: Domain length l(ξ,t) can be found as follows:

After: The length of one particular stripe domain l(ξ,t) can be found as follows:

 

- The stripe domain was assumed to be proportional to the field excess. Is it similar to the Rayleigh law used for domain wall motions?

Response:

The growth rate of the stripe domain is proportional to the field excess over the threshold value. Such dependence is obtained also for the wall motion due to step generation and growth in uniaxial ferroelectrics [26]. That’s why it is dissimilar to the Rayleigh law which is used for vibration of the domain walls as a whole [J. Phys. D: Appl. Phys. 29, 2057 (1996)].

 

The following text has been added in the manuscript at page 5, line 150:

It is necessary to pay attention that the used formula is dissimilar to the Rayleigh law which is used for vibration of the domain walls as a whole [27].

 

 

- Different fit parameters have been found on page 6. Can you compare them to the literature?

Response:

The used fitting of the total length of the switched stripe domains in increasing is original therefore it is impossible to compare the fit parameters to the literature.

- There are 15 publications related to V.Ya. Shur. (44%). Please reduce the self-citations.

Response:

We have reduced the self-citations in the manuscript. 

Reviewer 2 Report

Controlling the kinetics of the formation of nanodomain structures during polarization reversal is an important method for the formation of the domain structure of ferroelectrics and the electrical characteristics of these materials. An effective tool for such influence is the purposeful use of natural or special creation of artificial dielectric layers of such materials. Preliminary studies have shown that lithium niobate crystals with dielectric layers created by the so-called soft proton exchange method are particularly promising materials for domain engineering. Prior to the present study, systematic studies of these materials were not enough. Therefore, lithium niobate single crystals with a layer specially modified by soft proton exchange were the subject of this study devoted to "Abnormal domain growth during polarization reversal in lithium niobate crystal modified by proton exchange".

The studies of the polarization reversal processes of these materials carried out by the authors of this work revealed two qualitatively different types of evolution of their domain structure: the traditional growth of hexagonal domains in fields above 21.5 kV/mm and the anomalous growth of stripe domains oriented along Y crystallographic directions in the field range of 3.8 - 21.5 kV/mm. In the framework of the studies carried out, the authors studied the time dependence of the length of growing stripe domains and the average period of the resulting domain structure. Within the framework of the kinetic approach, the formation and growth of these stripe domains under conditions of inefficient screening due to the presence of a modified surface layer are analyzed. The anomalously low threshold fields for switching are attributed by the authors to the presence of a “built-in” field that facilitates switching, created by the composition gradient due to soft proton exchange. The motion of domain walls is theoretically described by the authors by the formation of steps on them and the motion of kinks along the walls.

Speaking about the work as a whole, it should be noted that the presented article is a detailed study of the effect of modification of the near-surface layer of lithium niobate on the processes of polarization reversal of this material. The fact recorded in it of the possibility of creating a quasi-periodic structure of stripe domains can be used to improve the characteristics of practically important devices for domain engineering. The article contains all the sections necessary for a detailed description of the revealed facts, is well illustrated, contains the necessary bibliographic support and can be published in its present form.

Comments for author File: Comments.docx

Author Response

We thank the reviewer for the thorough examination of our manuscript and positive review.

Reviewer 3 Report

This is an interesting study and worthwhile for publication in the present form. Only one query: please specify the wavelength of the excitation laser in the CRM.

Author Response

This is an interesting study and worthwhile for publication in the present form. Only one query: please specify the wavelength of the excitation laser in the CRM

Response:

We have specified the wavelength of the excitation laser in the CRM.

Page 2, Line 71,72

Added: with excitation laser on wavelength 488 nm.