The law does not allow you to ascribe your pension plan distributions to anyone other than your spouse, and it doesn't let you stop distributions to that person either. When divorce occurs, your ex-spouse is still entitled to some portion of the distribution plan. When written in accordance with the laws, the QDRO allows the ex-spouse the same distribution that they would have received if still married to the plan owner. If the plan owner should remarry, don't worry about your new spouse's benefits from the plan. Current and ex-spouses will each receive a proportionate share of the plan's distributions, determined by the length of each marriage and plan contributions made during those years.
IRAs function somewhat differently than qualified plans.
An IRA is generally considered the property of its owner. However, this assumes that there have been no contributions from earnings made during the marriage. If there have been contributions during your marriage, your spouse will have rights to some of the IRA assets as determined by state law. Such assets can be transferred tax-free by a written divorce decree. If you don't, you could be hit with a 20 percent withholding penalty for federal income tax.