Phase change system and phase change crucible for the separation of rare earth elements

A method of separating rare earth elements, the method comprising

• heating a composition comprising a first element and a second element in an inner chamber of a phase change crucible, wherein heating the composition phase separates the second element from the first element leaving a higher weight percentage of the first element in the inner chamber than was present in the composition and wherein the phase change crucible comprises:
• the inner chamber comprising an inner chamber wall extending from an inner chamber floor to an inner chamber upper end;
• an outer chamber comprising an outer chamber wall extending from an outer chamber floor to an outer chamber upper end, wherein the inner chamber upper end terminates beyond the outer chamber upper end and the outer chamber wall encircles the inner chamber wall;
• an inner collection region formed by the inner chamber wall and the inner chamber floor, the inner collection region housing the composition;
• and
• an outer collection region formed by the outer chamber wall, the inner chamber wall, and the outer chamber floor;
• and
• collecting the second element on a collection substrate positioned above the inner chamber of the phase change crucible.