Can extreme heat create alloys with much higher melting points?

I wonder if it is possible to create a new material with an exceptionally high melting point by using extreme heat and strong magnetic fields. The idea is to heat metals and molecular compounds until they become gases, then use powerful magnetic fields to contain them. These hot gases would then be rapidly cooled to form a new alloy.

Could this process result in a material with a higher melting point than existing ones, such as Ta₄HfC₅, which melts at 4215 degrees Celsius? My reasoning is that this might be similar to endothermic reactions, where adding enough heat triggers a transformation.

What do you think? If this does not work, how can an alloy with the highest melting point be achieved? Here is a link to an image of a graph.