You're producing a nanoscale material through macroscale processes
It's not quite like asking somebody with a hammer and chisel to produce a microchip, but depending on how many processes and sensitive variables affect your chemical processes, it ain't far off.
Maybes it's cooling rate. Maybe it's venting phosphorous gas. Maybe it's introducing ambient air. Maybe oxygen would be better. Maybe it should be faster. Maybe it should be introduced slower with faster cooling. Or slower cooling. Maybe the oven heats funny and placement matters given the distribution and the heating is the key.
Experimental chemistry can be a real pain, and it takes quite a lot to figure out what you've got.
It's not quite like asking somebody with a hammer and chisel to produce a microchip, but depending on how many processes and sensitive variables affect your chemical processes, it ain't far off.
Maybes it's cooling rate. Maybe it's venting phosphorous gas. Maybe it's introducing ambient air. Maybe oxygen would be better. Maybe it should be faster. Maybe it should be introduced slower with faster cooling. Or slower cooling. Maybe the oven heats funny and placement matters given the distribution and the heating is the key.
Experimental chemistry can be a real pain, and it takes quite a lot to figure out what you've got.