YBCO Oxygen Doping & Crystal Chemistry Simulator

YBa₂Cu₃O(6+x) crystal chemistry

Oxygen content, x 1.00

x = 0 → YBa₂Cu₃O₆ (chain O empty, insulator). x = 1 → YBa₂Cu₃O₇ (chain O full, optimally-doped superconductor).

Formula unit YBa₂Cu₃O₇.₀₀

Hole doping p

–

Critical T_c

–

Chain-O occupancy

–

Phase

–

How it works

YBa₂Cu₃O(6+x) is built from stacked layers along the c-axis: two CuO₂ planes (the superconducting planes) sandwich a yttrium layer, flanked by BaO layers, capped by a CuO chain layer whose oxygen sites (O1) are only partially occupied. Removing chain oxygen removes charge carriers (holes) from the CuO₂ planes, so the chain occupancy x directly sets the hole-doping level p felt by the planes.

p(x) ≈ 0.20 · x
Tc(p) = Tc,max · [1 − 82.6·(p − 0.16)²]

x → 0 (YBa₂Cu₃O₆) — chain sites empty, planes undoped, antiferromagnetic insulator, T_c = 0.
x ≈ 0.8 (optimal doping, p ≈ 0.16) — top of the dome, maximum T_c ≈ 93 K.
x → 1 (YBa₂Cu₃O₇) — chains full, slightly past the dome peak (mild overdoping), T_c a few K below the maximum.

Real-world relevance: this Tallon–Presland-style dome is the same doping–T_c relationship seen across the cuprate family (YBCO, BiSCCO, LSCO) — every cuprate superconductor is tuned through chemical doping, not just YBCO's oxygen content.

Y Ba Cu O (plane / apex) O (chain, variable)

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.