Theory 12/Dielectric Physics
Relaxors Need a Size Ratio
The claim
Relaxor behaviour appears when the ratio of polar nanoregion size to correlation length falls below a threshold, so the same composition can be a normal ferroelectric at larger regions.
01The mechanism
A relaxor requires the regions to be small enough that their orientations cannot lock together; above the ratio, they couple and the transition sharpens.
02Predictions
- P1Relaxor behaviour should track the ratio.
- P2Composition alone should mispredict across processing.
03Refutation
Relaxor behaviour tracking composition would remove the size ratio.