One Dimensional Oxygen Ordering in YBa2Cu3O(7-delta)

TL;DR

This paper presents an exact analytical model of oxygen ordering in YBa2Cu3O(7-delta), revealing temperature-dependent diffraction features and extending previous results to broader conditions, with good experimental agreement.

Contribution

It introduces an exactly solvable statistical mechanics model for oxygen ordering considering repulsive interactions, extending prior work to all delta and temperature ranges.

Findings

Diffraction peak splits at low temperatures for certain delta values.

Model matches experimental diffraction spectra.

Provides a compact analytical expression for diffraction intensity.

Abstract

A model consisting of oxygen-occupied and -vacant chains is considered, with repulsive first and second nearest-neighbor interactions V1 and V2, respectively. The statistical mechanics and the diffraction spectrum of the model is solved exactly and analytically with the only assumption V1 >> V2. At temperatures T ~ V1 only a broad maximum at (1/2,0,0) is present, while for ABS(delta - 1/2) > 1/14 at low enough T, the peak splits into two. The simple expression for the diffraction intensity obtained for T << V1 represents in a more compact form previous results of Khachaturyan and Morris[1],extends them to all delta and T/V2 and leads to a good agreement with experiment. [1] A.G.Khachaturyan and J.W.Morris, Jr., Phys.Rev.Lett. 64,76(1990)