The sheriff shall give the purchaser of any real property, sold upon execution a certificate of sale in which the property sold shall be described and the price for which it is sold stated. The certificate shall be evidence of the purchase at the price stated, and the officer shall return a duplicate thereof with the execution. No conveyance shall be made to the purchaser nor the possession delivered to him or her until the time for redeeming has expired. If the property is redeemed by the defendant as provided in this subchapter, the sale and certificate of purchase shall be null and void.