You can use LibrarySearch to find journal articles: type in your topic and then use the search tools menu to limit the format to article. Guide to finding journal articles on a topic using LibrarySearch - PDF.
When you want to find more specialised and specific journal articles, you may want to try using a database. Searching a database will help you find journal articles (and sometimes books, book chapters, reports and other published materials) that are scholarly, academic and peer-reviewed, and suitable for your assignments and research.
The following databases will find articles on a wide variety of topics. If you want a more subject-specific database, look at the suggestions made on other course resource help webpages (eg History for databases that specialise in history).
Academic Search Complete
A full-text database providing full articles, with their accompanying indexing and abstracts, across a wide range of subjects.
This database provides an archive of full-text articles from a wide range of academic journals. JSTOR does not give access to issues which are less than 3-5 years old but is very useful for older journal articles
Zetoc: electronic table of contents from the British Library
This database covers about 20,000 current journals and conference proceedings in science, technology, medicine, engineering, business, law, finance and the humanities. It covers material published since 1993 and is updated daily.