Q: What can I do if my paper has been "Under review" for 4 months?
This was my first time submitting to Materials Letters. For 4 months the status has been "Under review." Shall I write to inquire? How can I write properly?
You haven't mentioned the statuses before your paper moved to "Under review." Assuming this is external peer review, it's still quite a long time. You should definitely send a polite email to the journal inquiring about the current status of the paper and by when the reviews are expected to come in. As a rule of thumb, always send inquiries to the journal if there is no status change for more than a month.
Here's a template that you can use to write to the journal:
Dear Dr./ Mr./Ms. [Editor's Name],
I have submitted my manuscript titled [insert manuscript title and id] to your journal on [insert date]. The status has remained "under review" since [insert date when this status appeared.]. Since it has been over four months, I was wondering if there is any specific reason for the delay. It would be great if you could let me know by when I can expect the next status change.
Sincerely,
[Your Name]
Do read the following articles as you might find them useful:
6 Effective tips to help you communicate better with journals
Additionally, we have A practical handbook of templates for communicating with the journal which is really useful to write to the journal under different circumstances. Do take a look at it.
This content belongs to the Journal submission & peer review Stage