As an Arizona landlord you have the legal right to periodically enter your property. The law doesn't place limitations on why you want to enter the property. However, it is not a right without limitations and should not be used as a form of harassment or intimidation.
A.R.S. § 33-1343(D) states in part that, “the landlord shall give the tenant at least two days’ notice of the landlord’s intent to enter and enter only at reasonable times.” Although the law does not specify that the notice must be written (as opposed to verbal), it is a good idea to post written notice of intent to enter, or send via mail, so that you as a landlord have proof that you followed the proper procedure.
A.R.S. § 33-1343(A) states in part that “the tenant shall not unreasonably withhold consent to the landlord to enter into the dwelling unit in order to inspect the premises, make necessary or agreed repairs, decorations, alterations or improvements…” or show the property to potential buyers. If the tenant won’t allow you to enter the property, it is grounds for eviction.
Per, A.R.S. § 33-1343(C) the landlord may enter the dwelling unit without consent of the tenant in case of emergency. So, for example, if you see smoke billowing out of the windows you don’t have to wait for permission to enter and extinguish the fire.