`My understanding is Deacons can be married if they were married before becoming Deacons. They cannot marry after becoming Deacons.
Per Wiki:
http://en.wikipedia.org/wiki/Deacon#Roman_Catholicism
“The permanent diaconate can be conferred on single men 25 or older, and on married men 35 or older, but an older age can be required by the episcopal conference.[14] If a married deacon is widowed, he must maintain the celibate state. Under some very rare circumstances, however, deacons who have been widowed can receive permission to remarry. This is most commonly done when the deacon is left as a single father. In some cases, a widowed deacon will seek priestly ordination, especially if his children are grown.[15] (See also clerical celibacy.) The wife of a permanent deacon may be sometimes considered a partner in his ordained ministry. In many dioceses, the wife of the diaconal candidate undertakes the same education and training her husband does.”