A RAM after the computer is shutted down start is degradation of what contains, but if you cryogenically freeze the RAM, you will make the degradation process slower nearly arresting it. That work because the copper that is contained inside the RAM will become less conductor if the temperature is enough low. You will what you can do knowing that here an article about a use of the RAM in the forensics field
[code]https://www.zdnet.com/article/cryogenically-frozen-ram-bypasses-all-disk-encryption