Floating-zone growth and property characterizations of high-quality La2-xSrxCuO4 single crystals

TL;DR

This paper reports on the successful growth of high-quality La2-xSrxCuO4 single crystals using the traveling-solvent floating-zone method, with optimized procedures leading to crystals with excellent structural and superconducting properties.

Contribution

It introduces an optimized process for growing high-quality LSCO single crystals with minimal impurities and superior structural quality, verified by advanced characterization techniques.

Findings

Crystals achieved high structural quality with FWHM of 113-150 arcseconds.

Superconducting transition temperatures are 30 K, 31 K, and 38.5 K for different doping levels.

No impurity phases detected in the grown crystals.

Abstract

We have grown underdoped (x = 0.11, 0.12) and optimally doped (x = 0.16) La2-xSrxCuO4 (LSCO) crystals by traveling-solvent floating-zone (TSFZ) technique. In order to obtain LSCO single crystals of high quality, we have made much effort to optimize the preparation procedures. For example, we have adopted sol-gel route to prepare highly fine and homogeneous LSCO precursor powder, and used quite slow growth rate. The sizable grown crystal ingots are typically about 6.6 mm in diameter and 100 mm in length, and no impurity phases were detected. The high quality of grown crystals has been verified by double-crystal x-ray rocking curves, with full-width-at-half-maximum (FWHM) being only 113 ~ 150 arcseconds (or 0.03 deg - 0.04 deg), which are the best data reported so far for LSCO crystals. The superconducting critical temperatures (TC's) of the cuprate crystals are 30 K for x = 0.11, 31 K for x = 0.12 and 38.5 K for x = 0.16 samples according to magnetic measurements.