[TrailMixRaisin]

The topic on how hard or easy it is to replicate seems to be as fast changing as other information. The first time I read about it, it was deemed to be super easy as all you needed are the two base materials and a vacuum furnace. But with all the drama involved I would not be surprised if the process is actually very complicated.

[qingcharles]

The paper is vague unfortunately. Here are some of the questions Andrew McCalip has (and he is fairly far along the path of actually making LK99):

Precursors:

•What level of purity is required for the precursor materials?

•Are there any necessary preparatory steps for the precursors just before use?

•What are the required particle sizes for the precursor materials?

Thermal steps:

•What is the environment (air or vacuum) for the Lanarkite reaction?

•What are the temperature ramp-up and ramp-down rates for all three reactions?

•Are there any thermal annealing steps involved?

•How sensitive is LK99 to the duration of the final 925°C step?

Results:

•Could you elaborate on the observed differences between the bulk material and the thin film?

•Does the bulk material share the same composition as the thin film?

•How repeatable is the prescribed recipe, is SC behavior stochastic across samples?

•Could you provide details on the equipment used, setup photos, and procedures employed to measure the critical current in response to an applied magnetic field, as seen in figure 8 of paper 3?

Thin film deposition:

•What type of glass substrate was used in the vapor deposition process for the thin film?

•Could the exact set-point temperatures of the tungsten boat be provided, instead of ranges? (e.g., 550 ℃ to 900 ℃, 900℃ to 2000 ℃)

•In patent figure 22, from which region was the resistivity value taken? The light gray or the dark gray area?

https://twitter.com/andrewmccalip/status/1685891722675687424