]>Lattice Instability in High Temperature Superconducting Cuprates and FeAs Systems: Polarons Probed by EXAFS : Figure 5
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Figure 5: (a) Fourier transform magnitude curves of simulated E//ab EXAFS oscillations for undistorted (solid line) and distorted Cu O 4 -Cu O 4 units (red curve: JT Q 2 mode, purple curve: pseudo-JT (breezing) mode distortions). (b) Nearest neighbour contribution of simulated EXAFS oscillations for undistorted and distorted models. Interference of long and short Cu–O bonds give rise to beat features at 𝑘 ∼ 1 2 Å − 1 . (c) Experimental nearest neighbor Cu-O EXFS curves measured at various temperatures. Beat feature similar to (b) is observed at 𝑘 = 1 4 Å − 1 near 𝑇 𝑐 (40 K).