Crystal Growth and Doping Control of HgBa2CuO4+{\delta}, the Model Compound for High-Tc Superconductors

TL;DR

This paper presents a novel method for growing high-quality HgBa2CuO4+{ heta} single crystals, enabling precise doping control and structural analysis, advancing the understanding of high-Tc superconductors.

Contribution

The study introduces a new crystal growth technique and detailed doping control for HgBa2CuO4+{ heta}, including structural characterization and effects of gold doping.

Findings

Achieved high-quality single crystals with Tc up to 94 K.

Demonstrated precise doping control over a wide range.

Identified doping signatures using micro-Raman spectroscopy.

Abstract

A new method to grow very high quality single crystals of the superconducting HgBa2CuO4+{\delta} mercury cuprates is reported. The single crystals are platelet-shaped, with surfaces of high optical quality and good crystallographic properties. Annealing enables optimization of Tc up to Tcmax = 94 K. With adequate treatment, the doping level of the crystalline samples can be finely controlled in a wide under- and over-doped range. Complete structural characterization from single crystal X-ray diffraction data is given for the first time for different doping levels. The role of added gold on the doping is also investigated. The signature of under- and over-doping for both pure and gold-substituted crystals has been identified from micro-Raman spectroscopy measurements.