La. Stat. tit. 9 § 2946
It shall be unlawful for any seller in a bond for deed contract to require promissory notes to represent the purchase price or any portion thereof, if the property should be encumbered with a mortgage or privilege. Upon the payment to the escrow agent of the sum necessary to release the property, the seller shall execute a deed to the buyer and may then exact one or more mortgage notes to represent any portion of the unpaid purchase price. Should the property not be encumbered with a mortgage or privilege, and a note has been executed to represent all or a part of the price under the bond for deed contract, when the buyer shall become entitled to demand a deed, the seller shall execute an authentic sale and the notary passing it shall require the production of the note or notes and shall cancel them at the time of passing the sale.
La. R.S. § 9:2946