Nearly six months after the death of Robin Williams, the Academy Award-winning actor and comedian, his widow and his children have become engaged in a contentious legal dispute over his estate.

Court documents filed in December and January outline a bitter disagreement over money and property between the widow, Susan Schneider Williams, who was Mr. Williams’s third wife, and Zak, Zelda and Cody Williams, the comedian’s children from two previous marriages that ended in divorce.

At stake is not only a portion of the wealth that Mr. Williams accumulated in a film, television and stage career of some 40 years, but also cherished belongings that include his clothing, collectibles and personal photographs.

In their court papers, both sides display keen interest in such memorabilia — everything from Mr. Williams’s bicycles to his collections of fossils and toys — as tangible, deeply personal reminders of the irrepressible, manic imagination that drove his performances as a comedian and actor.