The cover letter is a letter that is usually submitted in the journal along with the manuscript, and it is, in fact, the first writing that an editor revises and according to it makes a decision on the article and selects the referee.
Therefore, it plays an important role in the process of reviewing your article. so, several things have to be done to write it.
The cover letter is not abstract; so, you should not copy the abstract into it!! In the first paragraph of the cover letter, you should introduce the title of your article, the authors, the research group, and your interest field. Then, it is essential to explain that this article is not submitted to another journal. Thereafter, briefly explain your goals and the results of the study.
Avoid addressing the details of the article. Remember that this letter should contain sentences that encourage the editor to review your article and refer it to appropriate referees. Thus, be careful when writing this letter.
After mentioning the points, in a separate paragraph put the list of research contributors, describe the practical applications of research, and how the current research can contribute to the advancement of future research. The final point is to observe subtle notes of writing and grammar. Be sure to send your cover letter to a specialist to do a grammar check for you.