Intel says no
Phase-change memory (PCM) exploits properties of chalcogenide alloy, the internal state of which varies between crystalline and amorphous phases with different levels of electrical resistance. These are used to indicate binary ones or zeroes.
Intel has stated that 3D XPoint technology is based on a bulk property change in the memory cell but isn’t actually PCM and Micron told us in 2016 that “Unlike Phase Change Memory, 3D XPoint technology uses a unique cross point architecture, enabling it to scale in ways that Phase Change Memory has not been able to accomplish.”
The scientists made their assessment in a research paper entitled “From Octahedral Structure Motif to Sub-Nanosecond Phase Transitions in Phase Change Materials for Data Storage”, published in Science China Information Sciences.
The authors reviewed phase-change random-access memory (PCRAM aka PCM) and declared:
We asked Chipzilla if the researchers were correct in their assertions. A spokesperson said: “Intel is not disclosing the materials used for 3D XPoint memory media, the underlying memory media used in Intel Optane SSDs and memory, or the manufacturing processes used.”
So if it walks like a duck and quacks likes a duck then it’s… Intel has refused to confirm. ®