How to write and publish a scientific paper - Barbara Gastel, Robert A. Day 2022
Copyright of unpublished materials
Rights and permissions
Publishing the paper
Copyright automatically begins the moment a work is created; it goes into effect the instant the pen leaves the paper or the fingers leave the keyboard. If you write a paper, design a figure, create a slide set, or the like, the copyright remains yours unless you transfer it to someone else.
Accordingly, if you post your materials on your website or share them in your institutional repository, they are already copyrighted. Ditto if you post your unpublished article in a preprint server. Journals vary as to whether they want materials that already have been posted. But the issue is separate from copyright.